roasting operations. Sulfur oxide re­leases from the autoclave vents are notsignificant because iron dissolved in theacidic autoclave slurry catalyzes thecomplete-oxidation of sulfide to sulfateinstead of more volatile sulfur dioxide.

In other parts of the process atMcLaughlin, atmospheric emissions arevery similar to more conventional goldrecovery operations. However, the reg­ulatory climate in the environmentallysensitive area of California surroundingthe mine made it necessary to forecasttypes and quantities of substances thatwould be released from all anticipatedair emission sources, and to verify thoseforecasts by performing source tests onthe commercial operating facility. CH2MHILL successfully completed the sourcetesting program following plant startupand stabilization in 1985. This is be­lieved to be the first time a commercial

gold recovery facility has been so ex­the atmosphere.

The McLaughlin Mine gold recoveryprocess also has several other favora­ble attributes, contributed in part by au­toclaving. One important feature is thatby oxidizing the sulfide fraction of theore, the potential for acid formation inthe tailings is removed. This eliminatesthe need for extraneous measures forcontrol such as enhanced containmentstructures.

Another benefit provided by auto­claving is a reduction in reagent con­sumption in the carbon-in-pulp (CIP)circuit. This is achieved by bypassingreagent-consuming constituents that aredissolved during autoclaving around theCIP circuit (via the decant neutraliza­tion/precipitation circuit in Figure 1). Anadditional benefit is that, because re­agent consumption is reduced, process

tailings contain lower concentrations ofresidual reagents. These levels are fur­suming components are recombinedwith CIP tailings for placement in thetailings impoundment.

The process at the McLaughlin Minehas earned acceptance for preservingenvironmental quality in an environ­mentally sensitive region of Californiawhile proving to be efficient and eco­nomic as well.

If you want more information on this subject,please circle reader service card number 77.

UMC Book Review Program

Metallurgical Calculations - Part IVA.E. Morris, James StephensonUniversity of Missouri-Rolla Rolla Research Center, U.S. Bureau of Mines

The exclusive book reviews appearing in Journal of Metals each month are anexceptional member service. A cooperative effort with the University Materials Coun­cil (UMC) enables the Journal to maintain the most comprehensive review programanywhere in the field of materials engineering. The UMC represents the departmentheads of the metallurgy and materials science schools in the United States.

The UMC book review program operates through designated contact persons atparticipating universities, who disseminate review books acquired by the Journal. Ifyou are interested in being part of our mailing list, please contact Shirley Miller at(412) 776-9070.

than the main oxide lower the temper­ature of its transition to intrinsic con­duction, reduce the breadth of theforbidden zone and raise the reactivityof oxides. The study of the admixtureinfluence on properties of metallic ox­ides has clearly revealed a link betweenelectrophysical properties and reactiv­ity. The established regularity of admix­ture influence on electrophysicalproperties and the reactivity of metallicoxides makes it possible, in principle,to control the process of interaction be­tween metallic oxides and other agents.

Researchers have revealed the com­mon electronic nature of the conductiv­ity of metallic oxides and their reactivity.Their work indicates that a rise in theconcentration of free electrons in thesystem, necessary to intensify physicaland chemical processes, can beachieved by introducing donor additivesand other physical methods of influencebesides traditional heating. This discov­ery can be applied to intensify physicaland chemical processes in metallurgy,chemical technology, the production ofcomposites, semiconductor materialsand other economic sectors.

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JOURNAL OF METALS. January 1987

MAINFRAME SYSTEM:SHIMPO·GOTO

SHIMPO-GOTO Version III is writtenin FORTRAN 77 and is used for cal­culating molar amounts of variousphases at equilibrium in large chemicalsystems at a given temperature andpressure. The package allows a moreflexible input than Versions I or II. Inaddition, heat balance calculations maybe done by providing input of molal heatcontents, temperatures of transforma­tion for components below their reac­tion temperature, and heat contents ofcharge components. All data must becarefully prepared before execution, andthere is no way to change data after

entry because of batch processing. Mostconference attendees found the pro­gram to be the most difficult to evaluate,even with the assistance of workshoppersonnel. Once correct input of datawas achieved, the results were quicklyand accurately attained.

The has been the fourth installment ofan eight-part series which is examiningsome of the programs featured at theComputer Software for MetallurgicalCalculations Conference, which tookplace late in 1985 at the University ofMissouri-Rolla.

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