Abstract: A process for the purification of soil contaminated with organic material is provided. The preferred process generally involves superposed attrition and classification processes, which lead to removal and concentration of highly contaminated fractions. The process may also include a step of flotation whereby hydrophobic materials in the soil are released to an interface with air bubbles, and are floated to the top of a flotation cell. In preferred processes according to the present invention, soil to be treated is extracted from a contaminated site, and is broken into relatively small particles. These particles are preferably treated in attrition and classification steps, to remove fine, slow settling contaminated materials such as wood and fine soil materials. The resulting isolated coarser materials are then treated by flotation for a final polishing step.

Abstract: A process for the purification of soil contaminated with organic material is provided. The preferred process generally involves superposed attrition and classification processes, which lead to removal and concentration of highly contaminated fractions. The process may also include a step of flotation whereby hydrophobic materials in the soil are released to an interface with air bubbles, and are floated to the top of a flotation cell. In preferred processes according to the present invention, soil to be treated is extracted from a contaminated site, and is broken into relatively small particles. These particles are preferably treated in attrition and classification steps, to remove fine, slow settling, contaminated materials such as wood and fine soil materials. The resulting isolated coarser materials are then treated by flotation for a final polishing step.

Abstract: A process for producing ferroborons is disclosed. The process consists of reacting a boron compound such as calcined colemanite with a metal such as aluminum in the presence of iron. The solid state reaction followed by subsequent grinding and sintering steps optimizes boron recovery.

Abstract: A process to remove SO.sub.2 from mixtures by contacting SO.sub.2 -containing mixtures with a regenerable iron-bearing sorbent such as paint rock under reaction conditions to produce iron sulfide and an effluent containing reduced amounts of SO.sub.2.

Abstract: A method for recovering nickel from a waste material containing nickel and small amounts of iron or aluminum or a mixture thereof comprising the steps of:(a) removing the organic impurities from the waste material;(b) leaching the material with an acid after removal of organic impurities to provide an acid solution;(c) precipitating said iron and aluminum from the acid solution; and(d) recovering nickel from the acid solution.

Abstract: Disclosed is a process for refining a magnesium and nickel containing ore, comprising the steps of grinding the ore; preparing a slurry of the ground ore in sulfuric acid containing less than ten percent of water; adding water to the acid-ore slurry in an amount which is effective to initiate a sulfation reaction; allowing the sulfation reaction to continue, utilizing the heat of the sulfation reaction to heat the acid-ore slurry, whereby water-soluble metal sulfates and insoluble residue are formed; leaching the sulfation product with water to extract the water-soluble metal sulfates in solution; separating the metal sulfates solution from the insoluble residue; precipitating from the solution metals other than Mg as hydroxides; separating the solution from the metal hydroxide precipitate; concentrating the solution sufficiently to precipitate CaSO.sub.4 ; separating the concentrated solution from the precipitate; recovering dehydrated MgSO.sub.

Abstract: This application is directed to the use of ferrous sulfate for absorption of sulfur from gases containing the same. The invention is predicated on the reaction of the sulfur oxides with ferrous sulfate in the presence of oxygen to form principally ferric sulfate.

Abstract: A method for removing sulfur and arsenic from cobaltiferous ores and recovering an enriched cobalt product is described. The procedure involves the steps of(a) oxidizing said ore at a temperature of at least about 700.degree. C. to reduce the sulfur content of the ore to the desired level,(b) heating said oxidized ore with a reducing agent at a temperature of at least about 700.degree. C. to remove arsenic from the ore, and(c) recovering an enriched cobalt containing solid as the product of the process.

Abstract: A process for recovering iron, nickel and magnesium metal from low grade nickeliferrous ores is described. This process which requires little energy input comprises the steps of(a) grinding the ore to reduce the particle size of the ore,(b) preparing a slurry of the ground ore in sulfuric acid containing less than ten percent of water,(c) adding water to the acid:ore slurry in an amount which is effective to initiate a sulfation reaction,(d) allowing the sulfation reaction to continue utilizing the heat of the sulfation reaction, whereby water-soluble metal sulfates are formed,(e) leaching the sulfation product with water to extract the water-soluble salts of iron, nickel and magnesium from the insoluble residue, and(f) recovering the nickel, magnesium and iron from the leach solution.The desired metals which are recovered in this manner contain significantly reduced levels of undesirable silica.