Effect Grinding Speed and Ball Size on Mineral Liberation
Grinding is generally considered to be a size reduction operation. However, in most cases the primary objective of grinding is the liberation of valuable minerals from gangue material, irrespective of the amount of size reduction required. If fracturing of an ore occurs in a random manner, it may be possible to use the grain size […]
Bioleaching Refractory Gold Ore
Bacterial extraction of gold from sulfide bearing ores has been studied by many investigators. If gold occurs finely disseminated within the sulfide ore matrix such as in pyrite, arsenopyrite and pyrrhotite, the leachant can not penetrate into the inside of solid ore in order to leach the enclosed submicron size gold particles. For their liberation, […]
Column Flotation Pilot Scale Testing
Flotation feed was obtained at the various preparation plants by diverting slurry from either the thickener feed, classifying cyclone overflow or fine refuse sump depending on the plant circuit. In each case, the slurry was obtained from a waste stream prior to any flocculant addition and stored in a 650 liter (170 gallon) agitated mix […]
Cryogenic Plant at Mining Metallurgical Processing Plants
In the 1940’s a top blown water-cooled oxygen lance was developed to inject oxygen into liquid iron. This process, the LD or BOF process technique, today is used in 65% of the world’s steel production, and represents the largest oxygen market for temperature enhancement in steel and non-ferrous smelting applications. There are three major approaches […]
Gallium Solvent Extraction
Recently, details of a study optimizing gallium and germanium extraction from zinc residues using H2SO4 leaches was published. In the process, filtrates containing gallium and germanium along with other impurities such as iron, copper, zinc, and cadmium are produced. The focus of this paper is the recovery of gallium from these solutions. It has been […]
Sodium Silicate in Phosphate Flotation
Some factors adversely affect the efficiency of anionic flotation of phosphate in the absence of sodium silicate, thereby decreasing the concentrate grade. Impurities originally present on the quartz surface might be responsible for this adverse effect, but the precipitates heterocoagulated onto the surface of quartz also appeared to play a role. Dissolved ions, especially Ca++, […]
Making Titanium Pigments
Chemical Processes-Pigment Grade Titanium Dioxide by Hydrochloric Acid Leaching The following reactions give the chemistry of this process: CaTiO3 + 4HCl = TiOCl2 + CaCl2 + 2H2O The titanium is in solution as TiOCl2. It is then hydrolyzed to TiO2 as follows: TiOCl2 + H2O = TiO2 +2HCl The hydrolysis is brought about by dilution […]
Screening Concentrate to Remove Contaminants
This was a unique idea; to use a size separation device in a mineral separation. As metallurgists, we were taught in school to use any physical property difference available to make the mineral separation. The idea was a departure from conventional processing flowsheets employed by the majority of mineral processing plants. Plant testing began with […]
Grinding Coal Water Slurry
The pilot mill used was 44 cm i.d. and 60 cm i.l. with a volume of 91,250 cm and was fitted with six one-half inch lifter bars. The ball charge was made up of 2,200 one-inch balls for a bulk volume of 36,500 cm³ (40% loading and a void volume of approximately 13,700 cm³ (38%). […]
MBT 2 Mercaptobenzothiazole Flotation Collector
To study the effects of collector and hydrogen ion concentrations on the floatabllity of sulfide minerals, a series of flotation experiments were conducted in which flotation recoveries as a function of pH were measured by flotation tests in a laboratory flotator. The results of flotation tests using -100 +200 mesh size galena particles as a […]