Mining by Nuclear Explosives Fracturing
The copper in many large low-grade and small high-grade deposits cannot be economically recovered by conventional methods because the value of the copper content of the large low-grade deposits is less than the cost of recovery, and the tonnage in the small deposits is not enough to amortize a recovery plant. These deposits are suitable […]
Gold Distribution & Variability in Drill Core
The extreme variability in gold mineralization in drill core is revealed through the detailed sampling experiment. This variability is that naturally present on the smallest scale that can be found by fire assay. With samples of substantially larger volumes, less variability would be found. Most of the variability is associated with among-feet rather than within-feet […]
Electrowinning Rare Earth Elements
Electrowinning Rare Earth Elements like Neodymium, praseodymium, and didymium, were (obviously) electrowon from their oxides dissolved in fluoride melts. The use of a thermal gradient cell resulted in recovery of nodules of well-coalesced metal with a purity of 99.9 percent. Current efficiencies of up to 83 percent were obtained. Shallow immersion of fluted anodes allowed […]
Electrorefining Vanadium
A molten salt, inert-atmosphere electrorefining process was developed for producing ductile vanadium from commercial vanadium. Five different chloride electrolytes were utilized. The chief impurity elements in the commercial vanadium were aluminum, iron, molybdenum, nitrogen, and silicon totaling 8 percent. Refining reduced these elements to produce 99.0 to 99.6 percent vanadium. The process was especially effective […]
Conveyor Belt Fire Hazard
This investigation showed that neoprene, polyvinyl chloride, and rubber belts ignite readily when subjected to an impinging flame. Although pre-heating of the belt is not necessary for ignition, preheating does increase the probability of developing a self-sustaining flame after ignition. The time and total quantity of heat required to ignite neoprene were greater than those […]
Electric Smelting Lead Zinc
Based on the results obtained during this investigation, slag-resistance, open-bath electric smelting of complex lead-zinc sinter is not considered feasible. Inherent characteristics of electric smelting promote and permit excessive transfer of iron, lead, and volatile slag constituents to the condenser when smelting normal lead-zinc sinter. Reaction of these constituents with zinc causes its degradation. Consequently, […]
Mine Sampling Assays
A continuing problem in mine evaluation, planning, operations, and production scheduling is the necessity of assigning some value for the grade of mineralization which occurs in the area lying between two sample points. This problem is particularly prevalent in evaluating ore deposits because of the usual wide-spaced drilling and sampling in the exploration phase of […]
Recover Hydrofluoric Acid from Fluosilicic Acid Waste
This report describes a preliminary investigation of methods for recovering hydrofluoric acid (HF) from waste byproduct fluosilicic acid (H2SiF6). Fluosilicic acid is generated by plants processing phosphate rock in the manufacture of fertilizer; most phosphate rock contains 3 to 5 percent fluorine in the form of the mineral fluorapatite (Ca3(PO4)3F). When this fluorine-bearing material is […]
Calcium Vanadate Precipitation and Processing
This report presents the results of a Bureau of Mines laboratory investigation to ascertain if the precipitation of calcium vanadate from low-tenor alkaline leach solutions can be practically employed for producing marketable technical-grade oxide (red cake) or ammonium metavanadate (AMV). The research was undertaken during the development of an autoclave process for extracting vanadium from […]
Iridium Electrodeposition
Adherent, coherent electro-deposits of iridium 15 mils thick and alloys of iridium 4 mils thick were formed in argon atmosphere from fused cyanide electrolytes. The use of pure iridium to prevent oxidation appears limited to temperatures under 1,000° C because of volatility of the oxide of iridium. Iridium alloyed with platinum-group metals such as platinum, […]