This application pertains to methods of recovering metals from metal sulfides that involve contacting the metal sulfide with an acidic sulfate solution containing ferric sulfate and a reagent that has a thiocarbonyl functional group, wherein the concentration of reagent in the acidic sulfate solution is sufficient to increase the rate of metal ion extraction relative to an acidic sulfate solution that does not contain the reagent, to produce a pregnant solution containing the metal ions.

Methods are provided for the recovery of scandium from scandium-bearing ores. The methods included leaching under atmospheric conditions using various acids. Solution impurities are removed from the leachate and scandium values are then recovered from the leachate.

This application pertains to methods of recovering metals from metal sulfides that involve contacting the metal sulfide with an acidic sulfate solution containing ferric sulfate and a reagent that has a thiocarbonyl functional group, wherein the concentration of reagent in the acidic sulfate solution is sufficient to increase the rate of metal ion extraction relative to an acidic sulfate solution that does not contain the reagent, to produce a pregnant solution containing the metal ions.

Aspects of the invention include a method of producing a cement material comprising step of: first reacting a calcium-bearing starting material with a first acid to produce an aqueous first calcium salt; second reacting the aqueous first calcium salt with a second acid to produce a solid second calcium salt; wherein the second acid is different from the first acid and the second calcium salt is different from the first calcium salt; and thermally treating the second calcium salt to produce a first cement material. Preferably, but not necessarily, during the second reacting step, reaction between the first calcium salt and the second acid regenerates the first acid.

Methods and apparatus for controlling odor of wastewater are described. An example method includes dispensing a solution in wastewater. The solution comprises an iron-nitrate compound mixed in water. In some examples, the iron-nitrate compound is ferric nitrate and/or ferrous nitrate. In some examples, the solution further includes an iron ion source different from the iron-nitrate compound, such as an iron salt like ferrous sulfate, ferrous chloride, or the like. The dispensing can be by using a feeding station in a wastewater collection system.

A process for improving the grade and optical quality of zircon, comprising: baking a mixture of a zircon feed and concentrated sulphuric acid at a baking temperature in the range of from 200 up to 400 C., and for a time to form water leachable sulphates with impurities therein including at least iron and titanium; leaching the baked mixture to dissolve the leachable sulphates; and separating the zircon from the leachate containing the leached sulphates, which separated zircon is thereby of improved grade and optical quality.

A water treatment composition includes a water soluble film formed into a sealed pouch. The pouch contains a composite of a phosphate removing substance, a polymer flocculant, or an enzyme, or any combination. The phosphate removing substance, the polymer flocculant, and the enzyme are bound to each other within the composite. The pouch is added to a body of water. The pouch dissolves to release the compounds and treat the water.

A method of producing electrode active materials includes generating a source material of titanium (Ti) and a source material of iron (Fe) from an ilmenite, and performing a operation to the source material of Fe and the source material of Ti. The operation includes determining a content of Fe or Ti in the source material of Fe or Ti, preparing an intermediate mixture having the source material of Fe or Ti and other required source materials, ball-milling and drying the intermediate mixture, and sintering the intermediate mixture to form the electrode active materials.

A method of producing electrode active materials includes generating a source material of titanium (Ti) and a source material of iron (Fe) from an ilmenite, and performing a operation to the source material of Fe and the source material of Ti. The operation includes determining a content of Fe or Ti in the source material of Fe or Ti, preparing an intermediate mixture having the source material of Fe or Ti and other required source materials, ball-milling and drying the intermediate mixture, and sintering the intermediate mixture to form the electrode active materials.

In a method of producing iron(II) sulfate heptahydrate, a material containing iron oxide is subjected to a pre-processing treatment to adjust the particle size and/or the water content thereof. The pre-processed raw materials are then reacted with sulfuric acid, followed by a reduction treatment with elementary iron to produce iron(II) sulfate. The iron(II) sulfate may be purified and crystallized as iron(II) sulfate monohydrate prior to crystallization as iron (II) sulfate heptahydrate