Bacterial Copper Leaching

Bacterial Copper Leaching

Among several suggested new processes for treating marginal ores in the United States, none is more intriguing than the possibility of extracting metals from low-grade materials by the action of microorganisms. One phase of a Federal Bureau of Mines investigation toward developing such a procedure was to isolate and identify specific chemosynthetic iron- and sulfur-oxidizing … Read more

Dry Filter Cake using Radiant Heat – Reduce Moisture

Table of ContentsTheoretical ConsiderationsTest ApparatusTest ProcedureSynthetic SlurriesThickener Underflow ProductFroth Flotation ConcentrateEconomic Considerations This report stems from a study by the Bureau of Mines of the possibility of reducing coal filter-cake moisture by applying radiant heat directly to the filter cake while under vacuum during the drying phase of the filter cycle. One disk of a … Read more

Titanium Gadolinium Phase Diagram

The results of this investigation indicate that the titanium-gadolinium phase diagram is composed of a single eutectic reaction and a peritectoid reaction at the alpha-beta transformation. The eutectic isotherm has been established at 1,240 ± 10° C. and extends from approximately 1 pct. gadolinium to beyond 99 pct. gadolinium at this temperature. The solid solubility … Read more

Extract Aluminum from Aluminum Silicon Alloys

Table of ContentsAluminum Extraction ProcessApplication of Extraction Process, Procedure and ResultsCrude Alloy FeedInduction-Heated UnitElectrical-Resistance-Heated UnitGas-Fired UnitStudy of Process ConditionsPressureLeaching The following conclusions are drawn from the results of these investigations: The reflux leaching method is an effective means for extracting aluminum from crude Al-Si alloy. Aluminum obtained by this method will contain from 1 to … Read more

Treating Oxide Copper Ore Acid Curing and Countercurrent Decantation Washing

Table of ContentsAcid Cure ProcessLeaching Studies Laboratory TestsContinuous Tests The bench-scale and continuous pilot plant tests demonstrated the technical feasibility of treating oxidized copper ores by acid curing and counter-current decantation washing in drag classifiers without the necessity of resorting to a sand-slime separation. Success of the process depended upon addition of a flocculant, such … Read more

Thermochemistry of Erbium

The heats of solution of erbium chloride in water and in hydrochloric acid and of erbium oxide in hydrochloric acid were determined. The results reveal a discrepancy of 10.5 kcal. per gram-atom between the heats of combustion and solution of erbium reported in the literature, the heat of combustion being more negative. The heat of … Read more

How to Make Zirconium Diboride Directly from Zircon

Table of ContentsExperimental ProceduresEquipmentMaterialsMethod of PreparationExperimental ResultsDiscussion of Results Zirconium diboride of a quality comparable to that produced commercially from zirconium dioxide may be synthesized directly from zircon. The quantities of residual carbon and silica are not excessively high, but it is believed that some refinements in procedure may lower these percentages. The grain size … Read more

Zirconium Gadolinium Equilibrium Diagram

The investigation of the zirconium-gadolinium equilibrium diagram revealed a eutectic system with limited terminal solubilities and one peritectoid reaction. The eutectic point occurs at about 82 percent gadolinium. The eutectic isotherm, at 1,220° C., extends from about 12 to 99+ percent gadolinium. The peritectoid isotherm, at 890° C., involving the alpha-beta transformation of zirconium, extends … Read more

Fine Coal Gravimetric Separation

Table of ContentsTest ApparatusTest ProcedureEffect of Time and Speed of CentrifugationPrecision of Centrifugal SeparationsEffect of Testing Method on the Amount of Misplaced MaterialEffect of Particle Size on Centrifugal SeparationsEffect of Type of Separating Liquid on the Recovery of Float CoalComparison of Centrifugal with Static Float-and-Sink Test Results A centrifugal float-and-sink test procedure has been developed … Read more

Sulfide Oxide Lead Zinc Transitional Ore Treatment Processing Method

Table of ContentsBeneficiation ResearchFroth FlotationDeslimed pulpUndeslimed PulpFlotation Plus Gravity SeparationHeavy-Media Separation and TablingFlotation of Oxidized Zinc The mineral dressing research here reported is part of a continuing program by the Bureau of Mines to develop new or improved concentration processes for oxidized or partly oxidized lead and zinc ores. A sample of low-grade sulfide-oxide, lead-zinc … Read more