Methods for measuring the sulfur content in a plurality of individual sulfur-containing fiber or article samples, comprising: a) contacting a plurality of samples with a solution comprising potassium hydroxide to convert the sulfur to potassium sulfate; b) concurrently and individually combusting the plurality of samples from step a) in a furnace at a temperature of greater than 650 C. to remove essentially all organic materials to produce a plurality of residues; c) dissolving each of the pluralities of residue in concentrated nitric acid to form individual residue solutions; and d) analyzing the individual residue solutions with Inductively Coupled Plasma (ICP) Emission Spectrometry to determine the sulfur content of each sample.

A method for treating sulfide in an aqueous fluid comprises contacting the fluid with an oxidizer in the presence of a sulfur dye or sulfurized vat dye. In one embodiment, the method comprises treating sulfide contaminated water by contacting the contaminated water with air in the presence of a sulfur dye or a sulfurized vat dye. The method is useful for remediating industrial, agricultural, and municipal waste water.

A method for treating sulfide in an aqueous fluid comprises contacting the fluid with an oxidizer in the presence of a sulfur dye or sulfurized vat dye. In one embodiment, the method comprises treating sulfide contaminated water by contacting the contaminated water with air in the presence of a sulfur dye or a sulfurized vat dye. The method is useful for remediating industrial, agricultural, and municipal waste water.

A method for treating sulfide in an aqueous fluid comprises contacting the fluid with an oxidizer in the presence of a sulfur dye or sulfurized vat dye. In one embodiment, the method comprises treating sulfide contaminated water by contacting the contaminated water with air in the presence of a sulfur dye or a sulfurized vat dye. The method is useful for remediating industrial, agricultural, and municipal waste water.

A method for treating sulfide in an aqueous fluid comprises contacting the fluid with an oxidizer in the presence of a sulfur dye or sulfurized vat dye. In one embodiment, the method comprises treating sulfide contaminated water by contacting the contaminated water with air in the presence of a sulfur dye or a sulfurized vat dye. The method is useful for remediating industrial, agricultural, and municipal waste water.

Sulfur copolymers having high sulfur content for use as raw materials in 3D printing. The sulfur copolymers are prepared by melting and copolymerizing one or more comonomers with cyclic selenium sulfide, elemental sulfur, elemental selenium, or a combination thereof. Optical substrates, such as films and lenses, are constructed from the sulfur copolymer via 3D printing and are substantially transparent in the visible and infrared spectrum. The optical substrates can have refractive indices of about 1.75-2.6 at a wavelength in a range of about 500 nm to about 8 m.

Sulfur copolymers having high sulfur content for use as raw materials in 3D printing. The sulfur copolymers are prepared by melting and copolymerizing one or more comonomers with cyclic selenium sulfide, elemental sulfur, elemental selenium, or a combination thereof. Optical substrates, such as films and lenses, are constructed from the sulfur copolymer via 3D printing and are substantially transparent in the visible and infrared spectrum. The optical substrates can have refractive indices of about 1.75-2.6 at a wavelength in a range of about 500 nm to about 8 m.

Magnesium oxide produced by a process is used as a neutralizing agent for preliminary neutralization treatment of a leached slurry obtained by leaching a nickel oxide ore at a high temperature and pressure with sulfuric acid added. A neutralizing agent is added to a leachate, obtained by leaching a nickel oxide ore, to separate impurities, and a sulfurizing agent is added to the resulting neutralized solution to obtain nickel and cobalt sulfides, followed by separating the sulfurized solution; discharge waste water, obtained by adding a neutralizing agent to the sulfurized solution to separate aluminum and manganese, is concentrated to precipitate and separate calcium contained in the discharge waste water as calcium sulfate; the resulting solution is concentrated to precipitate magnesium in the solution as magnesium sulfate; the magnesium sulfate is roasted with a reducing agent to obtain magnesium oxide and a sulfurous gas; and the magnesium oxide is washed.

Magnesium oxide produced by a process is used as a neutralizing agent for preliminary neutralization treatment of a leached slurry obtained by leaching a nickel oxide ore at a high temperature and pressure with sulfuric acid added. A neutralizing agent is added to a leachate, obtained by leaching a nickel oxide ore, to separate impurities, and a sulfurizing agent is added to the resulting neutralized solution to obtain nickel and cobalt sulfides, followed by separating the sulfurized solution; discharge waste water, obtained by adding a neutralizing agent to the sulfurized solution to separate aluminum and manganese, is concentrated to precipitate and separate calcium contained in the discharge waste water as calcium sulfate; the resulting solution is concentrated to precipitate magnesium in the solution as magnesium sulfate; the magnesium sulfate is roasted with a reducing agent to obtain magnesium oxide and a sulfurous gas; and the magnesium oxide is washed.

Compositions and methods of producing composite materials for use as a cathode in electrochemical cells. Elemental sulfur is mixed with tungsten sulfide (WS.sub.2) to form a composite mixture. Organic comonomers may be added to the composite mixture. The composite mixture is reacted to form the composite material. Electrochemical cells with cathodes containing the composite material demonstrated improved battery performance.