researchanddevelopment.pdf

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RESEARCH & DEVELOPMENT

5 Research & Development

The Science and Technology programmes (S & T)of the Ministry of Mines, Government of India,

initiated in 1978, cover the disciplines of Geology,Exploration, Mining & Environment, Bioleaching,Beneficiation, Rock Mechanics, Ground Control andNon-ferrous Metallurgy. Fifteen new projects havebeen received and there were six ongoing projectsduring 2007-08.

The highlights of work carried out during 2006-07 and 2007-08 by various research organisationsand industries relating to mineral beneficiation andmining & environment are given below :

1. BENEFICIATION

1.1 Beach SandBeneficiation studies on beach sand samplesfrom Srikakulam district, (AP) (NML).

Studies were undertaken on beneficiation andseparation of heavy minerals from beach sandsample from Srikakulam (A.P.). The modal analysisof the sample indicated that it contained about25% heavies. Initial preconcentration of thesample was carried by spiralling to remove majorsilica. The heavy fraction was subjected to hightension separation of both the conducting andnon-conducting materials to separate ilmenite,ru t i l e , garne t , z i rcon and s i l l imani te . Thesillimanite was further concentrated to + 98%purity by flotation. The project is under progressto prepare bulk sillimanite concentrate.

Studies on offshore and onshore samples fromRatnagiri (NML).

NML and CMERI scientists collected offshoreand onshore samples from Ratnagiri sea bed andcoast. Offshore mining technology was developedby CMERI. Mining operation and bulk samplecollection were also conducted by CMERI. Spotsample collection was done by NML scientists.Scanning Electron Photomicrograph and EDAXspectral analysis of onshore beach sand andoffshore sands were carried out.

1.2 ChromiteR & D studies on Chromite ore sample (IMMT).

Beneficiation studies were carried out on(1) Chromite ore beneficiation (COB) plantmiddlings (2) plant tailings containing about 20%Cr2O3 and (3) low grade ferruginuous chromite orecontaining about 15% Cr2O3. Flow sheets havebeen developed to recover most of the chromitevalues from the sample. It is possible to recovergood grade chromite concentrate from middlingby simple combination of hydrocyclone andtabling.

It is possible to obtain 20 wt% of chromiteconcentrate containing 48% Cr2O3 at around 50%recovery involving gravity concentration andflotation from the COB plant tailing. It was alsoestablished that about 22wt% of the concentratecan be obtained containing 48% Cr2O3 at around70% recovery from the sub-grade chromite orecontaining 15% Cr2O3.

1.3 Copper OreBeneficiation of Copper Ore from Khetri Mines(Jhunjhunu) for M/s HCL.(IBM).

A copper ore sample from Khetri Mines ofKhetri Copper Complex, Jhunjhunu district ,Rajasthan of M/s Hindustan Copper Ltd wasrece ived a t Modern Minera l Process ingLaboratory and Pilot Plant, Nagpur with theobjective of developing a process to obtain acopper concentrate assaying more than 19% Cuwith more than 90% recovery.

The as received sample assayed 0.83% Cu,57.95% SiO2, 3.71% S(T), 16.68% Fe(T). Byadopting flotation route a concentrate assaying19.27% Cu, 11.77% SiO2, 27.45% S(T), 33.61% Fe(T)with Copper recovery of 89.3% could be obtainedat 20% pulp density . When the flotation wasconduc ted a t 30% pulp dens i ty a copperconcentrate assaying 19.54% Cu with 88.5%copper recovery (Weight % yield 3.8) could beobta ined . Both the concent ra tes meet therequirements of the party.

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Upgradation of a Copper Ore from BanwasMines, Khetri Copper Complex for M/s HCL(IBM).

A copper ore sample from Banwas Mines,Khetri Copper Complex, Jhunjhunu district ,Rajasthan of M/s Hindustan Copper Ltd wasrece ived a t Modern Minera l Process ingLaboratory and Pilot Plant, Nagpur with theobjective of developing a process to obtain acopper concentrate assaying more than 19% Cuwith more than 90% recovery.

The as received sample assayed 1 .59%Cu, 17.23% Fe(T), 3.47% S(T). By adoptingflotation route, a copper concentrate assaying20.87% Cu with 90.6% Copper recovery (wt %yield 6.6) could be obtained at 20% pulp density.Flotation at higher pulp density - 36% solids, acopper concentrate assaying 20.98% Cu withcopper recovery of 90.1% (wt % yield 6.6) couldbe obtained. Both the concentrates meet therequirements of the party.

Recovery of Bulk Copper-Zinc Concentrate fromCu-Zn ore sample from Khnaiguiyah deposit,Saudi Arabia of M/s SAFCO (IBM).

A copper-zinc ore sample from Khnaiguiyahdeposi t , Saudi Arabia of M/s SAFCO Geo-Environmental Consultants, Hyderabad receivedat Modern Mineral Processing Laboratory andPilot Plant, Nagpur assayed 7.56% Zn, 0.98%Cu, 30.51% SiO2, 13.17% Fe, 5.46% S, 0.01%Sr and 0.025% TiO2. The objective was to developa flow sheet to yield the zinc concentrate assaying50% Zn with less than 8% Fe and a copperconcentrate assaying more than 25% Cu withdesirable recovery. The flotation process yieldedthe bulk copper-zinc concentrate assaying 18.22%Cu, 16.89% Zn, 20.48% SiO2, 19.98% S, 7.48% Fe(T),0.12% Cd, 2.733 ppm Au and 29.5 ppm Ag with74.1% Cu recovery (wt % yield 4.0). Zincconcentrate obtained after one cleaning assayed55.76% Zn, 1.09% Cu, 8.5% SiO2, 26.6% S, 3.14%Fe(T), 1.1% Al2O3, 0.19% Cd, 2.524 ppm Au and61.63 ppm Ag with 74.2% Zn recovery (wt % yield10.1). Due to complex nature of Cu-Zn mineralsassociation with each other, it was inferred that iti s no t feas ib le to p roduce ind iv idua lCu concent ra te mee t ing smel te r schedule

particularly in respect of Zn concentrate, however,from a bulk Cu-Zn concentrate metal values couldbe recovered by Tol l Smel t ing orhydrometallurgical operations.

Evolution of suitable process flow sheet toobtain Copper concentrate from Banwas minesof M/s HCL (IBM).

The copper ore sample from Banwas mine wassent by Khetri Copper Concentrator of M/sHindustan Copper Limited with an objective toevolve a suitable process flow sheet to obtain acopper concentrate with more than 90% recovery.The sample contained 1.90% Cu, 19.0% Fe(T) and7.40% S(T). By flotation process, a copperconcen t ra te assay ing 24 .98% Cu could beobtained with 93.7% Cu recovery. The grade andrecovery ach ieved i s more than the va luestipulated by the party.

1.4 CobaltImprovement o f Cobal t ex t rac t ion f romroas t reduced po lymeta l l i c sea nodules inammoniacal solution, supported by Departmentof Ocean Development, New Delhi (NML).

Polymetallic sea nodule available in the oceanfloor is the future resource for Cu,Ni, and Co.NML Jamshedpur has developed a process routecomprising reductive roast and ammonial leachingfor the extraction of these strategically importantmetals from the sea nodules. Due to variousreasons, the Co recovery was never more than 60%through Cu and Ni extraction was more than 90%in th i s p rocess . There fore , s tud ies onimprovement of the cobal t recovery in thereduction-roast ammonial leach process of oceannodules has been undertaken in this project.Earlier activities in this project were on identifyingvarious reasons of low cobalt recovery and itspossible remedy, also development of improvedprocess in bench sca le wi th h igher coba l trecovery. During last one year the main activityunder this project was scale-up of the developedbench scale process. Accordingly, five large scaleroasting and leaching compaigns were conducted.Large scale roasting was carried out by using avertical retort furnace. Grounded raw noduleswere mixed with LD oil, palletised and air & oven

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dried. These dried samples were subjected forroasting at 750oC in a continuous mode. Each largescale roasting compaign generated about 300 kgof good quality roasted product. These productswere used for subsequent leaching campaigns.The leaching conditions maintained in the largescale studies were similar to that of the benchscale one. Five numbers of leaching campaigns,each comprising six leaching tests (up to 5th

recycle) were carried out during this period. Theresults were almost identical and encouraging withan average of 81.2% Co, 93.5% Cu and 94.8% Nirecovery.

Separation and recovery of copper, nickel andcobalt from leach liquor of sea nodules by bulksulphide precipitation-chloride leaching-SX-EWroute , supported by Department of OceanDevelopment, New Delhi (NML).

A suitable down stream operation for the largevolume of dilute solution generated from theprocessing of sea nodule by the existing processwas needed to be developed. It was planned toadopt bulk sulphide precipitation of the valuablemetals like copper, nickel, cobalt and zinc fromthe dilute leach liquor followed by redissolutionin chloride media and SX-EW operation. Thepresent process will substantially reduce thevolume of leach liquor and hence will reduce thesize of equipment, cost of capital and energy.Earlier the detailed study was made on completeprecipitation metal values from dilute leach liquorand dissolution study of bulk sulphide was carriedout in chloride media in presence of chlorine gasin order to obtain concentrated leach liquor fordown stream processing. To avoid chlorine gasdissolution, electro-leaching of bulk sulphide inbrine solution was carried out with simultaneouselectro winning of copper. Experiments werecarried out in a rectangular glass vessel usinggraphite electrodes. An average current efficiencyof 73% was obtained with applied anode currentdensity of 400 A/m2. As a part of separationprocess of metals from leach liquor, copper wascompletely separated by selective electro winningand sulphide precipitation followed by zincextraction using TBP. Cobalt from the leach liquor

was extracted with alamine 336 at higher chlorideconcentration. Initially, the studies have beenmade at various operating conditions e.g., atdifferent chlorideion concentration, O:A ratio, etc.using the organic 20% Alamine 336 and 10%isodecanol in kerosene. The results show thatwi th increas ing O:A ra t io , the percen tageex t rac t ion of coba l t inc reases and a t O:Aof 2:1, almost 96% of cobalt is extracted from1.78g/L Co, 25.70g/L Ni and 270.0g/L Cl-solution.The two stages counter current simulation studywas also validated the results and almost completeextraction of cobalt was possible with negligibleamount of nickel extraction.

1.5 FluoriteReduction of Silica content in low grade fluoritesample from Dongargaon, Warora (IBM).

A fluorite sample from Dongargaon,. Warora ofMaharashtra State Mining Corporation (MSMC) wasreceived for bench scale beneficiation studies fromM/s Shaila Industries, Yavatmal to develop a suitableprocess flow sheet that may yield a fluoriteconcentrate assaying minimum 85% CaF2 grade alongwith maximum limitation of 6% SiO2 , 2.5% CaCO3

and 3.6% R2O3, respectively. The as received sampleassayed 52.96% CaF2 , 37.41% SiO2, 3.25% CaCO3,0.85% Al2O3, 1.14% Fe2O3 . A fluorite concentrateassaying 88.24% CaF2, 6.95% SiO2 and 0.42% Al2O3

with 49.9% CaF2 recovery (wt% yield 30.4) could beobtained. Though the desired 6% SiO2 limitation ofsilica could not be achieved, the attained grade ofthe concentrate in terms of CaF2 is significant in viewof the complex ore nature.

1.6 GraphiteCharacterisation, beneficiation and utility

study of some graphite deposits from ArunachalPradesh (NEIST)

An ambi t ious R & D pro jec t fo rcharacterisation, beneficiation and utility studyof some graphite deposits from Arunachal Pradeshwith support from Ministry of Mines, Govt. ofIndia, New Delhi has been initiated.

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Utilisation of graphite pre-float (HZL).During the early years of Rajpura Dariba plant

operation, some quantity of lead-graphite bulkconcentrate was accumulated due to metallurgicaldifficulties during lead smelting. Laboratoryflotation and gravity separation experiments wereconducted to upgrade the graphite pre-float(concentrate) of RDM. Though silver upgradationcould take place to some satisfactory levels, leadloss cou ld no t be p reven ted due to c loseassociation of the minerals and in the sizes theyexist. These studies gave opportunity to derivemetallurgical treatment methods by combiningwith those smelter intermediates presently notconsumed.

1.7 Iron OreBeneficiation of a low grade iron ore samplefrom Sub grade dump of Sankalapuram Iron OreMine (IBM).

A low grade Iron Ore Sample No.2 from Subgrade dump of Sankalapuram Iron Ore Mine,Kar iganur, Hospe t Ta luk , Be l la ry d i s t r ic t ,Karnataka was received from M/s R.B. SethShreeram Narsingdas, Hospet to evolve a flowsheet yielding calibrated lumpy ore (+65% Fe)/Sinter grade concentrate(63.5% Fe)/Pellet gradeconcentrate (+65%Fe). The as received orecontained 54.29% Fe(T), 10.66% SiO2, 6.32% Al203,1.01% FeO, 0.20% MgO and 2.86% LOI.

Beneficiation process comprising grinding,tabling and magnetic separation produced aconcentrate assaying 65.02%Fe(T), 1.62% FeO &0.95% LOI with 78.0% Fe(T) recovery with a wt.%yield of 63.10. The concentrate produced meetsspecifications for pellet grade.

Iron Ore sample from Sagar Taluk, Shimogadistrict, Karnataka (IBM).

Iron Ore sample from Sagar Taluk, Shimogadistrict, Karnataka sent by Shri B. Kumar GowdaMine Owner, Sandur Karnataka assayed 33.8%Fe(T). 17.7% FeO, 42.6% SiO2, 1.13% Al2O3 and4.03% LOI. The objective was to produce an ironconcentrate suitable for pellet manufacture. Aconcentrate assaying, 66.79% Fe(T), 4.09% SiO2

and 0.60% Al2O3, with an over all recovery of71.0% Fe(T) with wt % yield 37.3 could be

obta ined. This concentra te i s sui table forapplication in pellet Industry.

Beneficiation of iron ore fines, sponsored byM/s. Fluid O Bulk, Kolkata (NML).

The iron sample from Hospet was received atNML for beneficiation studies. The sample wasof -10 mm fraction. The sample assayed 56.73%Fe, 5.45% Al2O3, 7.34% SiO2 and 6.15% LOI. Theobjective of the studies was to develop a flowsheet for obtaining a concentrate of +63% Fe.Mineralogical studies revealed that the sample islateritic type and major iron bearing mineral isgoethite. The liberation indicated for completel iberation could be achieved in f iner sizes.Beneficiat ion s tudies using combinat ion ofscrubbing, washing, cycloning, etc. were used toupgrade the ore.

Beneficiation of iron ore fines from Barbil area(NML).

The iron ore fines sample was received fromBarbil area to find the suitability of the sample forbeneficiation for pelletisation. The prime objectiveof the project was to carry out a detailed beneficiationstudies to develop a flow sheet for beneficiation oflow grade iron ore fines for pellet making. The ironore fines of -10 mm sample were received at NMLand the sample assayed 63.2% Fe, 3.46% Al2O3 and3.02% SiO2. The alumina level has to be broughtdown to 1.5%. The studies involved scrubbing,grinding to one mm and spiralling. The spiral tail isto be treated by Wet High Intensity MagneticSeparation (WHIMS). The experiments so far haveindicated that concentrates from spiral could beobtained with alumina of 1.56%. More experimentsare underway to increase the yield throughoptimisation of spiral and WHIMS.

Column flotation studies on iron ores, sponsoredby M /s. JSW Steel Ltd,Vidyanagar, Karnataka(NML).

The project involved beneficiation of iron orefines of M/s JSW to improve the quality of theconcentrate by identifying a suitable reagent andutilising the column flotation technology. Basedon laboratory scale flotation studies, the reagentwas identified and the process parameters offlotation optimised. The pilot column (0.5 m dia.)

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was shifted to the plant site of M/s JSW atToranagallu and test work was done on the screwclass i f i e r over f low under the op t imisedparameters. The alumina could be reduced to2.0 - 2.5 from 3.5 - 4.5% with increased weightrecoveries as compared to the existing recoveriesfrom the classification by cyclones.

Pilot Plant beneficiation of iron ore fines,sponsored by M/s. Bhahmani Rivers PelletsLimited (NML).

M/s. Bhahmani Rivers Pellets Limited hassponsored the project on iron ore fines samplesfor beneficiation from Orissa. The samplesassayed 59.72% Fe, 3.90% Al2O3, 3.45% SiO2 and5.78% LOI, respectively. The different schemes forbenef ic ia t ion s tud ies were fo l lowed us ingcombination of scrubbing, washing, cycloning,spiral and grinding of the oversize material andmagnetic separation. To improve the recovery ofthe tailing was further ground and subjected tomagnetic separation. The studies indicated thata combined product with a yield of 70-75%assaying 63.6% Fe, 2.4% SiO2 and 2.6% Al2O3

could be ob ta ined which i s su i tab le aspelletisation feed.

Pilot Plant beneficiation of iron ore samples,sponsored by M/s. Essar Orissa Steel Limited(NML).

At the instance of Essar Orissa Steel Limitedbeneficiation studies were carried out on iron orefines samples from Orissa. The samples assayed60.39% Fe, 3.85% Al2O3, 3.45% SiO2 and 4.70% LOI,respectively. The objective of the study was todevelop the flow sheet for obtaining a concentrateof +64% Fe for pellet feed. Difference schemeswere followed for beneficiation studies usingcombination of scrubbing, washing, cycloning,spiral and grinding of the oversize material andmagnetic separation. Recovery from tailing wasattempted by further grinding and subjecting tomagnetic separation. The studies indicated that acombined product with an yield of 70-75%assaying 64.2% Fe, 2.35% SiO2 and 2.55% Al2O3

could be ob ta ined which i s su i tab le as

pelletisation feed. About 5 tonnes of concentratewas produced for evaluation by the sponsor.

R & D Studies on Iron ore Samples ( IMMT).

An integrated process flow sheet has alsobeen developed to beneficiate low grade lump ironore (Fe 61.7%, SiO2 2.8% and Al2O3 3,4%) fromBarbil region to produce quality products for blastfurnace, sponge iron, sinter making and pelletmaking plants. Two alternative flow sheets havebeen suggested which can produce quality rawmaterials for iron making such as lumps, calibratedore, sinter feed and pellet feed with more than64.0% iron content and less than 2.0% Al2O3 at85% yield. The process ensures super qualitypellet feed with 63% Fe. More efforts are requiredto recover iron values from the tailings whichcontain 49.1% Fe with 8.8% SiO2 and 10.9% Al2O3.

It has been possible to prepare good qualityof pellets after grinding the concentrates from jigand magnetic separator to 80% passing below 45-micron size. It was observed that iron ore fineshaving specific surface area of 1.31 m2/g or moreare required to produce pellets with sufficientstrength. The pellets showed good compressivestrength of 250 kg/pellet when subjected to heathardening.

Low grade iron ore fine samples from Kasia,Sesa Goa, Banspani, Rungta and Guali mines fromBarbil-Joda region, were taken up to develop suitableflow sheet to upgrade various types of ironconcentrates to more than 64% Fe with about 4.0%Al2O3 and SiO2 for its use in pelletisation plant. Aconcentrate of above 64% Fe with more than 72%yield could be obtained by grinding, hydrocyclone,spiral and magnetic separation techniques.

Another sample from Barbil area was takenup to recover additional iron values from -1 mmfine material by magnetic separation technique.Benef ic ia t ion s tud ies have shown tha t aconcentrate of 63.67% Fe with 15% additional yieldout of 25.4% natural fines could be obtained from0.5 mm slimes by Wet High Intensity MagneticSeparator (WHIMS).

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Blue dust reject sample from Shree Gulab Minesand Minerals, distt. Jabalpur, M.P. (IBM).

An iron ore (Blue Dust) reject sample fromShree Gulab Mines and Minerals, distt. Jabalpur,M.P. containing around 55% Fe (T) was receivedfor development of flow sheet to produce amarke tab le g rade i ron concen t ra te . Thebenef ic ia t ion process evo lved compr i sedcrushing of sample to -30 mesh (0.5mm) followedby hydrocycloning, stub cycloning and wet highintensity magnetic separation which yielded acomposite concentrate assaying 63.33% Fe withtotal iron recovery of 92.8%. Based on the processdeveloped the party has initiated erecting of acommercial plant. The recovery of values frommine rejects is quite significant and addressesaspects of mineral conservation.

Characterisation and bench scale beneficiationstudies on a BHQ Sample from Nandi HalliMines, Hospet, Bellary, distt., Karnataka forM/s BMM Ispat Ltd (IBM).

A BHQ Sample from Nandi Halli Mines,Hospet, Bellary, distt., Karnataka for M/s BMMIspat Ltd was received with an objective toproduce an iron concentrate suitable for industrialuse with a high recovery. The as received sampleassayed 40.20% Fe (T), 40.60% SiO2, 0.66% Al2O3,0.0029% TiO2, 0.01% P, and 0.77% LOI.

Gravity separation of sample ground to minus200 mesh yielded a composite iron concentrateassaying 64.59% Fe(T) and 5.76% SiO2 with a Ferecovery of 44.7% (wt % yield 27.5).

Characterisation and mineralogical studiesrevealed that about 40% of the hematite grainscarry extremely fine grained inclusions of quartz.At coarser sizes a high grade concentrate couldnot be obtained because the interlocking of quartzwith iron oxides at places is of very complex natureand most of the quartz grains carry very fineinclusions of quartz .It was observed that even atfine grinding sizes, the grade of the concentrateimproved but the weight percent yield andrecovery was low due to the fact that the finesgenerated during grinding are joining the tailings.Hence, a high grade concentrate (+65% Fe) withhigh recovery could not be obtained.

BHQ Dump Iron Ore sample from Sandur,Bellary dist., Karnataka. (IBM).

A low grade dump iron ore sample designatedas BHQ dump sample assayed 44.89% Fe(T), 0.5%FeO, 32.19% SiO2 and 2.58% Al2O3 was received atRODL, Bangalore. The sample was sent by M/sV.S. Lad & Sons, Bellary dist., Karnataka (collectedfrom S.J. Harvi Iron Ore Mines, Laxmipura village,Sandur, Bellary) for upgradation. Hematite was thepredominant mineral. A composite magneticconcentrate assaying 64.95%Fe(T), 5.03% SiO2

and 0.69% Al2O3 with 50.3% Fe recovery with 33.8wt.% yield was obtained. The above concentrateproduced from dump is a significant achievementas it may find industrial application after blendingsuitably.

1.8 LimestoneBench scale beneficiation studies on low gradesample from M/s Madras Cements Ltd (IBM).

A low grade limestone sample received fromM/s Madras Cements Ltd for bench scalebeneficiation studies assayed 42.67% CaO, 72.33total carbonate, 17.42% SiO2 and 34.13% LOI. Theobjective of the studies was to produce a limestoneconcentrate assaying +80% total carbonate with asilica content below 14%. Flotation was the routeadopted to achieve the desired concentrate.

The cleaner concentrate was produced athigher pulp density assayed 87.52% T.C. with atotal carbonate recovery of 90.7% (wt % yield 75.2).The SiO2 content is 6.92%.

The rougher concentrate obtained at low pulpdensity, assayed 85.88% T.C and 7.80% SiO2 withtotal carbonate recovery of 94.6% (wt % yield 79.9).

Both the concentrates produced meet thespecifications stipulated by the party and aresuitable for cement manufacturing.

Pilot plant scale beneficiation studies carriedout on a low grade l imestone sample fromSattankulam area, Tamil Nadu received fromM/s Madras Cements Ltd (IBM).

By adopting flotation a limestone concentrateassaying 49.29% CaO, 7.16% SiO2 and 0.77% MgOwas obtained from a sample assaying 31.10% CaO,35.58% SiO2, 0.85% MgO and 25.01% LOI with a

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CaO recovery of 86 .5%. The concent ra teproduced meets the specifications for use in thecement manufacture.

Upgradation of Low Grade Limestone fromKarikoil (IBM).

A low grade limestone sample from KarikoilArea, Tamil Nadu, sent by M/s Madras CementsLtd, assayed 30.52% CaO, 36.30%SiO2, 0.47% MgO,and 24.97% LOI. The object of the investigationwas to conduct Pilot Plant scale studies to confirmthe laboratory scale results. By adopting flotationroute to achieve stipulated specifications, alimestone concentrate assaying 48.16% CaO,0.34% MgO, 7.80% SiO2 and 38.96% LOI with89.8% CaO recovery could be obtained. The flowsheet developed at IBM yielded a high gradeconcentrate which finds application in cementmanufacture.

Benef ic ia t ion of s i l iceous l imestone fromJayanthipuram Mine, sponsored by M/s.MadrasCements, Chennai (NML).

Beneficiation of low-grade limestone fromJayanthipuram mines of M/s MCL by flotation isinvestigated. The microscopic examination of thesample indicated that the calcite is interlockedwith gangue minerals and the same can be liberatedbelow the particle size of 40 microns. Directf lo ta t ion using sodium oleate and reverseflotation (flotation of gangue minerals) usingcationic collector was studied. The flotation datasuggest that the beneficiation of limestone bothby direct and reverse flotation processes iseconomically viable. The silica content wasbrought down to 7% from initial value of 14%.The CaO content was improved to above 50% fromits initial value of 42% with a weight recovery of75%. Further, beneficiation by flotation columnwas tried and the results were compared to that ofconventional flotation. The difference was foundto be marginal in terms of grade and recovery.Based on the test work, a flow sheet for thebeneficiation of Jayanthipuram limestone wassuggested. Draft report has been submitted toM/s MCL for comments.

Upgradation of Limestone samples from DungriLimestone Quarry for M/s ACC, Orissa (IBM).

M/s ACC Ltd sponsored three low gradelimestone samples namely BCW-I, BCW-II andBCW-III from Dungri Limestone Quarry, BargarhCement Works, Bargarh, Orissa for assessing theupgrada t ion poss ib le in the sample fo rapplication in the Cement Industry.

The beneficiat ion process developed byO.D. Lab., IBM indicated that a concentrateassaying 75 – 80% T.C. could be obtainedexcept in sample No. BCW-III (R.I. No. 1764)as it is very low grade. The results were evaluatedby ACC and helped them in prepar ing thecomposite sample to be sent for flotation studiesin O.D Laboratory of IBM so that the compositeconcentrate obtained find i ts application inCement Industry.

Dry benef ic ia t ion of low/marginal gradel imes tone for the i r su i tab i l i t y in cementmanufacture (NCBM).

The low grade sample received from KesoramCement with the nature of the raw material finegrained highly silicious. The chief contaminentswas silica (fine grained crypto crystalline). Theresults achieved were increase in CaO content from45.82% to 47.27% and reduction in SiO2 from13.34% to 11.55% at minus 60 micron size (weightrecovery of 83.5%).

The low grade sample received from UltraTech Cement Ltd with the nature of the raw materialfine grained, structurally deformed limestone inter-bedded with carbonacious shale. The chiefcontainments were silica & sulphur (mainly pyrite).The results achieved were CaO content increasedupto 49.3% and silica content reduced upto 5.05%.In case of high silica limestone (weight recoveryupto 70%). CaO content increased upto 45.39%and silica content reduced upto 12.19% in case ofhigh sil ica l imestone (weight recovery upto91.94%). Sulphur content can be reduced upto0.09% in limestone.

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The low grade sample received from Maratha Cementwith the nature of raw material fine grained limestonewith shale. The chief containments were silica andsulphur ( mainly pyrite). The results obtained wereCaO content increased upto 45.79% and silica contentreduced upto 2.64%. In case high silica limestone(weight recovery upto 85.21%).

Characterisation of limestone resources of NERegion for value addition and rational utilisation(NEIST).

Process for beneficiation of limestone locatedat Lumshnong, Jayantia Hills, Meghalaya andNew Umrangshu, North Cacher Hills District,Assam for making value added process for usingin iron & steel, paper, lime, sugar industries, etc.were developed. The project was completed inApril 2007 and final report submitted to Ministryof Mines, Govt. of India, New Delhi.

1.9 Lead & ZincRecovery improvement in Rajpura Dariba Mine(HZL).

Keeping in mind to enhance the grade andrecovery at Rajpura Dariba process in lieu of thecomplexity of ore from different Rajpura Dariba minesections, test work was taken up to produce asuitable bulk concentrate with Rajpura Dariba oreinstead of separate Lead and Zinc concentrates. Forthis, closed cycle flotation test work with thelaboratory Mini flotation Unit was carried out duringNovember 2007 and March 2008 in two phases.Successfully developed the process to minimise theimpurities and achieve desired quality for bulkconcentrate at lab scale that could be treated throughpyro-process for lead, zinc and silver metals. Thishas shown considerable step-change in overallmetals recovery improvement.

Minimising the misplacement of Zn in Pbconcentrate and Pb in Zn concentrate (HZL).

A flotation process for Rampura Agucha orewas developed at laboratory scale using newreagents to reduce the misplacement of Zn in Leadconcentrate and Pb in Zinc concentrate. This is anexploratory type work in finding new opportunitiesin process development. Laboratory test work was

taken up during July-September 2007. Test work wasconducted with Sodium bicarbonate, SodiumPhosphate and Sodium Polyphosphate reagents.Results indicated decrease in RAMzinc misplacementwith lead concentrate. Considerable reduction in themisplacement of zinc in lead concentrate and somelead in zinc concentrate were achieved using oresample from Rampura Agucha with sodiumphosphate reagent.

Silver concentrate production fromLead-Silver residue (HZL).

This is one of the alternatives tested as ameans of producing Ag rich concentrate from lead-silver cake, a leach residue from Chanderia lead-zinc smelter. A novel flotation process wasdeveloped to produce silver-rich concentrate fromres idue . There was cons iderab le s i lve rupgradation in to concentrate produced.

Silver recovery from Moore Cake - a leachresidue from Zn Smelter (HZL)

The process deve loped was tes ted byproducing silver concentrate in the two tonnesper day pilot plant by HZL. The silver wasupgraded from 300 ppm in the field to 2800-3000ppm in concentrate with 50% Ag recovery. Thetest work based on batch flotation tests wasexper imented . La te r c lose cyc le t es t wasconducted using mini flotation circuit.

Pyrite concentrate from beneficiation planttailing : (HZL).

Beneficiation tailings contain silver valuesand rejected pyrite. Due to major proportion as heavysulphide mineral in the tailing, pyrite concentrationrecovers some of the silver. Laboratory flotationexperiments were conducted to identify thefeasibility to produce pyrite concentrate from thelead-zinc flotation tails. Flotation studies withRampura Agucha tailing, ground to PP80 300 and400 mesh sizes were carried out in February -March2008 to recover pyrite and silver in the flotationconcentrate. Iron and silver contents were improvedwith increased fineness but finer grinding reducedtheir recovery by some extent, indicatingfurther optimisation of different parametersfor cost-effectiveness of the process.

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Bulk concentrate from beneficiation plant tailings(HZL).

Earlier in June-July 2004, test work on productionof Lead-Zinc-bulk concentrate from RAM tailing wasundertaken and optimum grade and parametersestablished. To further optimise zinc grade andrecovery in bulk concentrate, a project is undertakenin Oct’07 by gravity and flotation tests. Lab Gravitytests did not indicate scope for improvement.Flotation Test work was planned in early 2008,through recycling the middling and tests with groundtailing. Mini flotation tests under open cycle processcould not further enrich bulk concentrate, whereasclosed cycle tests indicated a bulk concentrate with9% Zn at 40% recovery under a set of parameterscombination.

Beneficiation of Lead - Zinc Sample from Latio-ka-Khera Project for MECL (IBM).

Mineral Exploration Corporation Limited, Nagpursent a sample from Latio-ka-Khera Project, Railmagra,Rajsamund, Rajasthan to RODL, Ajmer, with an objectiveof evolving a suitable beneficiation process flow sheetfor the recovery of lead and zinc. The as received sampleassayed 0.85% Pb, 4.80%Zn, 15.35% Fe(T) and 21.28%SiO2. By adopting flotation route, a lead concentrateassaying 62.78% Pb with 48.7% Pb recovery (wt% yieldof 0.6) and a zinc concentrate assaying 51.46% Zn with87.2% Zn recovery (wt% yield 8.5) could be obtained.Both the concentrates are of suitable grade for use inlead & zinc smelting.

1.10 ManganeseRecovery of manganese from leached sea nodulesresidue and toxicological studies of the waste,supported by Department of Ocean Development,New Delhi (NML)

During processing of Polymetallic Sea nodulesa substantial quantity of residue containing 20% Mn,10% Fe and 8% Si is generated which constitute 70%of the weight of the nodules treated. In order toimprove the overall economics of the process, it isnecessary to recover manganese either as metal orFe-Si-Mn alloy. The objective of the present studyis to produce standard grade Fe-Si-Mn from theleached sea nodules residue. For this, leachedresidue was blended with Mn ore/Fe-Mn slag/Mnmetal to have the required Mn/Fe ratio to produce

standard grade Fe-Si-Mn by smelting route.Attempts were also made to recover the manganeseas Fe-Si-Mn by two stage smelting of leached seanodule residue without any blending with the abovementioned Mn containing materials. Severalexperiments were conducted on 20 kg scale tooptimise the various parameters viz quantity ofreductant, soaking time etc. to achieve the standardgrade Fe-Si-Mn and good Mn recovery. The resultsof these experiments were presented in the last RC.Based on the above studies, the two stage smeltingprocess was decided to be tried on 350 kg scale inthe newly set up Fe-Si-Mn production pilot plant.Six nos. of campaigns were carried out on pilot scale.Standard grade Fe-Si-Mn was produced.

Processing of polymetallic sea nodules for recoveryof valuable metals, supported by Department ofOcean Development, New Delhi (NML).

Polymetallic sea nodules, better known asmanganese nodules obtained from deep ocean floor,contain valuable metals like Cu, Ni, Co and Mn.Available estimates show that availability of strategicmetals like Ni and Co in manganese nodules is about5 and 40 times higher, respectively, than that in landbased resources. Absence of economic resource ofNi and Co together with fast depleting Cu scenarioin India, made policy makers to think of exploitingthe polymetallic sea nodules of the adjoining IndianOcean. It is in this context, NML, Jamshedpur wasentrusted with the task on developing a suitabletechnology for extraction of valuable metals from thesea nodules, by the Ministry of Earth Sciences, Govt.of India. NML has developed a process on pilotscale for the metals extraction from sea nodulesfollowing the “Reduction roast-Ammonia Leaching- Solvent Extraction - Electrowinning-Leach residuetreatment” route. The recoveries of metals on pilotscale processing of sea nodules are Cu-95%, Ni-95%and Co-80%. Manganese recovery in the form ofstandard grade Fe-Si-Mn from the leached seanodules residue has been made by smelting route onpilot scale with the Mn recovery of about 75%.

R & D Studies on Manganese ore sample (IMMT).Mineralogical and geochemical characte-

r isat ion of low-grade manganese ores frommanganese formations of Koraput-Raigada sectorwere taken up.

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Representative Mn-ore samples from Koka andLeliguma in Raigad district were collected andcharacterised in respect of their mineralogy andchemistry. Both the ores are of low-grade type anddominantly contain higher oxy-hydroxide manganeseminerals. The gangue constituents are quartz,feldspar and kaolinite. The Koka Mn-ore containsaround 17% Mn and 25% Fe, mostly contributed bygeothite. In contrast, the Leliguma Mn-ore shows23% Mn, 6% Fe but is rich in phosphorus (P2O5:>1%), mostly contributed by apatite. Preliminarybeneficiation through roast reduction followed bymagnetic separation techniques showed appreciableupgradation of Koka manganese ore.

1.11 MarbleNingha Marble quarry of M/s JaiprakashAssociates Ltd. Dalla Cement, Sonbhadra distt.,U.P. for development of suitable beneficiation flowsheet for segregation of marble from quartzite(IBM).

A quartzite bearing marble sample was receivedat Modern Mineral Processing Lab & PP, Nagpur.The concentrate obtained finds application as asweetner in cement manufacture. The as receivedsample assayed 67.71% T.C., 35.21% CaO, 30.58%SiO2, 1.03% Fe2O3, 0.08% Al2O3, 0.63% MgO and29.95% LOI. The flotation concentrate obtainedassayed 86.8% T.C., 45.91% CaO, 11.85% SiO2, 0.07%Al2O3, 1.39% Fe2O3, 0.66% MgO with 87.7% recoveryand 68.8% wt. yield. The concentrate obtained findsapplication in cement manufacture as desired by theparty.

2. MINING2.1 National Institute of Rock Mechanics (NIRM)

The Insti tute has been extending itsR & D support to the industry in the following areas:

1. Hard RockMines/Metalliferrous mines.

2. Coal Mines.

3. Hydroelectric & Tunnelling Projects.

4. Other Civil Construction Projects.

The Institute took two S&T projects and 25industry sponsored projects in 2006-07. By the endof 2007-08 investigations were completed for 25projects and the work is in progress in 20 - oddprjects.

Non-coal minesThe key areas of research were geotechnical

studies, numerical modelling, geophysicalexploration and ground control investigations forhard rock mines and design of controlled blastingand laboratory testing of samples. The major areasof research included:

* optimum design of mining operations andexcavation systems;

* design of support system for improving safety,conservation and productivity;

* prediction of unknown subsurface features; and

* monitoring stability of excavations.

Support is also extended in areas ofenvironmental studies, exploitation of dimensionalstones and seismological studies.

NIRM also investigated ground stability of theopen slopes at Hutti gold mine throughinstrumentation and monitoring. NIRM has beenassisting CDOS in setting up a Test House fordimensional stones at Jaipur.In addition slopestability studies were carried out for designing theultimate angle of the pit slopes in opencast mines ofMML in Bellary district, Karnataka.

Coal MinesOne of the major thrust areas of the Institute is

to improve safety and productivity of theunderground coal mines in the country. NIRM isinvolved in assessing the feasibility of new miningmethods and safe roof supports in coal mines.

The strata control investigations in this sectorinclude:

* Rock mass characterisation, and RMR studies;* Design of rock reinforcement systems;* Coal mine pillar design;

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* Development of new mining mehods forincreased safety and productivity;

* Study of parting behaviour in multiple seamextration; and

* Mapping of barriers around old workings fromunderground.

The Institute undertook designing method ofwork under special conditions studies mostly in themines of South Central Coalfields Ltd (SCCL). NIRMhas also conducted studies of caveability of the roofstrata, design of method of extraction of pillars andstudy into extent of abutment loading trend anddesign of advance support during pillar extractionby stowin.

The Insti tute has been awarded a majorcollaborative S&T project by Ministry of Coal tostudy the caveability in longwall panels.

Hydroelectric projectsThe Institute has been involved in conducting

rock mechanics studies required for excavations inseveral hydroelectric projects in India. Main areasof rock engineering investigations carried out byNIRM in this field include:

* Investigations for determination of the insitustress and deformability properties

* Geophysical investigations for bed rockdelineation and stratigraphic mapping

* Instrumentation and monitoring.* Numerical modelling for stress analysis and

design of support systems; and* Design of controlled blasting parameters.

Investigations were carried out at variousprojects including Tala hydroelectric project(Bhutan), Sardar Sarovar Project (Gujarat), Koldamhydroelectric Project (Himachal Pradesh), Larjihydroelectric Project (Himachal Pradesh), DibangMultipurpose Hydroelectric Project (ArunachalPradesh), Pykara Hydroelectric Project (Tamil Nadu),Malana Hydroelectric Project (Himachal Pradesh),Pala Maneri Hydroeloectric Project (Uttrakhand) andVarunavat Parvat in Uttar Kashi of Tehri Project.

During 2007-08, in situ investigatios weredetermined for four major hydel projects.

Civil Construction ProjectsNIRM has been involved in a big way in various

investigations.Investgations were completed of theprestigious Katra-Qazigund rail link project in the

mountainous terrains in Jammu & Kashmir.Geophysical investigations were carried out atvarious tunnel portals and bridge abutmentsproposed along the 140 km long railway line. Rocksamples from these sites are tested at NIRM todetermine their physico-mechanical properties.NIRM has been continuing the investigations relatedto geotechnical mapping and blast design for thefirst underground LPG storage cavern of the countrybeing constructed in Visakhapatnam. The institutehas also secured the project for surfaceinvestigations at an oil storage cavern site inKarnataka. Seismic survey was also done for mappingbed rock profile at Teesta Stage -II and Stage-VIprojects in Sikkim.

Testing ServicesIn addition to these field investigations, NIRM

has done extensive testing of rock samples as perinternational standards. The studies carried out onvarious rock samples include:

* Measurement of strain at high temperature underuniaxial and triaxialcompressive stressconditions.

* Thermomechanical behaviour of rocks.

Fundamental resarch in the area of engineeringand mechanical properties of rock joints under shear,and studies on Kaiser effect, were some of the uniqueresearch areas of the Institute in the field of FractureMechanics. Further, wire rope testing and non-destructive testing (NDT) of mining equipment/components are carried out on regular basis.

3. ENVIRONMENTIndianBureau of Mines (IBM)

Mining Research Cell of IBM has renderedcharge base consultancy work on environmentalManagement for the generation of baseline data forthe preparation of DIA & EMP, Ground vibrationstudies due to blasting, Geotechnical Investigationfor the design of cut &fill stoping, slope stabilityinvestigations, design of tailing dams, waste dumpstability analysis,dump management & solid wastemanagement.

Monitoring of Environmental Parameters at ShigaoIron Mine of M/s Fomento Goa.

This consultancy project on environmentalquality monitoring at Copila Gaichem Paul (Ghigao)Iron Ore Mine of M/s Fomento Industries, Goa, has

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been carried out for all the four seasons to monitorenvironmental parameters such as air, water, soil andnoise at the mine. The monitoring data has beenanalysed and found that the study has indicated thatall the environmental parameters monitored are withinthe prescribed limits as per the MOEF standards.The final report has been sent to the party. Thushelped the management to develop the propermitigation measures.

Geotechnical Investigations for Slope Stability atSaniem Iron Ore Mine of M/s Taulikekar & Sons(P) Ltd, operated by M/s Fomento Goa.

Slope Stability Investigations were carried outat Saniem Mine, where the footwall benchesdeveloped wide tension cracks. Geotechnicalinvestigations include field mapping of tensioncracks, monitoring by EDM surveys, installation ofborehole pie meters for strata monitoring andlaboratory testing samples for physico-mechanicalproperties. Numerical modelling of slope analysis hasbeen carried out using ‘Galena’ computer programme.The results indicated that the slopes can bemaintained at 28 slope angle with Factor of Safety of1.5 by detailed geotechnical analysis, proper supporttechniques and field instrumentation. Pit slope weredesigned upto a depth of another 40 meters to minethe ore body. Thus, mine management is benefitedby results of this investigation and it is producing2.0 lakh tonnes of iron ore.

Geotechnical Investigations for Design of NewTailing Stacks/Dams at Cuddegal Iron Ore Mine ofM/s Fomento Goa.

Two new tailing stacks/impoundments weredesigned in the form of in-pit dug dams to increasethe holding capacity by geotechnical investigationscarried out. These dams are designed with a factorof safety of more than 1.5 with environmentalconsiderations. This helped the mine owner inincreasing the holding capacity of tailings.

Geotechnical Investigations for Assessment ofStability of Waste Dumps at Deposit No.5 ofBailadila Iron Ore Project Bacheli, M/s NMDC Ltd.

Geotechnical investigations were carried out forthe assessment of stability of waste Dump Nos. 1, 2,3 and proposed Dump Nos. 4 & 5 at Bailadila IronOre Project of NMDC by collecting samples of dump

material and testing for its physico - mechanicalproperties. These results were utilised as an inputparameters for analysing stability of waste dumpswith varying slope angles and slope height, usingnumerical modelling technique. The study hasindicated that it could be possible to maintain dumpslope angle of 37 degree with a factor of safety ofmore than 1.5 limiting maximum height of 59 m. Basedon the future quantum of waste generation, two morewaste dumps were designed for proper dumpmanagement system.

Study of ground Vibrations due to blasting in Amliand Thandiberi limestone mines of M/s BinaniCements Ltd in Sirohi district of Rajasthan.

The study was carried out in two limestonemines to evaluate the effect of blast inducedground v ibra t ions over the nearby sur facestructure by monitoring with the help of blastingseismograph. The investigation revealed thatvibration levels are within the limit, which maynot cause damage to nearby residential structure.However, as per the results of regression analysis,the explosive charge per delay for Thandiberilimestone mine is suggested to be restricted to550 kg.

Study of Ground vibrations due to blasting, nearChittorgarh fort of Rajasthan, in connection withD.B.Writ Petition and compliance report pertainingto half year ending 30.06.2006.

As per the directives of Hon’ble High Court ofRajasthan blast vibrations monitoring was carriedout at Chittorgarh fort and submitted the study reportto Hon’ble High Court of Rajasthan, Jodhpur. Theinvestigations revealed that vibration levels due toblasting carried out byM/s Birla Cement Works andother nearby stone quarries, are within the limit,which may not cause any damage to fort area.

Study of Ground vibrations due to blasting atBangur underground Chromite mine of M/s OrissaMining Corporation Ltd.

Ground vibration monitoring carried out atBangur underground Chromite mine and i tsresponses on the sur face s t ruc ture wereevaluated. It has been revealed that there is noblast-induced damage to the surface structure.

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