Nitric Acid Oxidation Rates of Coal
Coals ranging in rank from lignite to anthracite, cokes carbonized at temperatures ranging from 520° to 1,180° C., and synthetic polymers have been oxidized by the standard method, that is, by boiling in 8-normal nitric acid. Some of these materials were also oxidized by one or two modifications of the standard method. Although the fusain […]
How to Process Gold Ores by Heap Leaching & Carbon Adsorption Methods
The heap leach cyanidation carbon adsorption electrowinning process developed has proved to be an economical method for exploiting low-grade gold ores and small isolated deposits not suitable for treatment by conventional cyanidation procedures. Heap leaching may be the most profitable method for processing selected gold and silver ores that do not require fine grinding and […]
Sodium Chloride in Explosives
Based on the analysis of the W50 values of 65 permissible-type formulations, with and without added sodium chloride of various particle sizes, it was concluded that: The addition of sodium chloride to an explosive has a highly significant effect in reducing its probability of igniting firedamp. Addition of small amounts of sodium chloride (about 3 […]
Determining Lime Magnesia and Titania in Slags
Standard methods of analysis for calcium and magnesium are involved and time consuming and generally require considerable analytical skill. Investigation of possible alternatives more suitable for rapid routine application led to a procedure developed for the rapid determination of calcium, magnesium, and iron in limestone, in which these cations are determined by a series of […]
Vacuum Distillation – Remove Volatile Metals
The rate of evaporation of a volatile metal from a metallic solution containing less volatile metals is determined by its partial pressure and its diffusivity. The concentration of a volatile metal will be less at the surface than in the interior of the metal; it will adjust itself to keep the rate of diffusion and […]
How to Reduce Titanium Tetrachloride
This investigation has demonstrated that finely divided titanium metal, titanium lower chlorides, or a mixture thereof can be produced at a temperature between 105° and 205° C. in a continuous operation. The relative quantities of metallic titanium and lower chlorides produced by the reaction are dependent upon the ratio of the feed materials used. For […]
Hot Potassium Carbonate Absorption
Hot carbonate purification will remove hydrogen sulfide from gas mixtures of low or high concentration of this component. The presence of some carbon dioxide in the feed gas is necessary for regeneration of the solution. Carbon dioxide aids in decomposing the bisulfide and retards formation of potassium sulfide. Carbonyl sulfide is hydrolyzed by the hot […]
Smelting Unfired Iron Ore Pellets
Fines and concentrates must be consolidated or agglomerated into larger masses before they can be smelted in a commercial blast furnace. Such agglomeration is usually done by sintering, pelletizing, nodulizing, or briquetting. Sintering has been the more common practice, but with the advent of taconite concentrates pelletizing is increasing in importance. Pellets in the blast […]
Improve Hydraulic Backfill Characteristics with Flocculants
Two practical methods for controlling the physical properties of mill tailings for underground stope backfill may be used. The first is classification to remove objectionably fine size fractions, and is commonly employed. The second method, flocculation, has had very limited application. It is the subject of this investigation. This report covers preliminary laboratory studies of […]
Rare Earth Oxide Bastnasite
A bastnasite concentrate, containing about 60 percent rare earth oxides, was sulfated with concentrated sulfuric acid to eliminate the carbon dioxide, fluorine, and silica. Calcination at 1,200° F. made the gangue matter insoluble, thus permitting the separation of the soluble rare-earth sulfates. Essentially 100 percent of the rare-earth elements were recovered by this procedure. Since […]