A method for purifying sodium bromide by the waste circuit board pyrolysis coke, belonging to the field of purifying sodium bromide and high-value utilization, and more particularly, relating to a method for reducing and purifying crude bromine salt enriched from waste circuit board smelting ash by using waste circuit boards pyrolysis coke. The main steps are as follows: carbonization conversion, purification filtration and vacuum exsolution. The pure sodium bromide crystal was obtained by reducing crude bromine salt enriched from waste circuit board smelting ash by using coke in waste circuit board pyrolysis residues, realizing the resource coupling and high-value utilization of the two wastes, avoiding the secondary pollution in the process of recycling the waste circuit boards. It has the characteristics of simple operation, high resource utilization rate and no tail liquid discharge.

A method for purifying sodium bromide by the waste circuit board pyrolysis coke, belonging to the field of purifying sodium bromide and high-value utilization, and more particularly, relating to a method for reducing and purifying crude bromine salt enriched from waste circuit board smelting ash by using waste circuit boards pyrolysis coke. The main steps are as follows: carbonization conversion, purification filtration and vacuum exsolution. The pure sodium bromide crystal was obtained by reducing crude bromine salt enriched from waste circuit board smelting ash by using coke in waste circuit board pyrolysis residues, realizing the resource coupling and high-value utilization of the two wastes, avoiding the secondary pollution in the process of recycling the waste circuit boards. It has the characteristics of simple operation, high resource utilization rate and no tail liquid discharge.

Provided is a method for producing an alkali metal halide, including causing a reaction of an alkali metal sulfide and a substance represented by the following general formula (1) in the absence of a solvent or in a solvent except for water: X.sub.2 (1), wherein X represents a halogen element.

Technologies relating to increasing hydraulic fracturing efficiencies in subterranean zones by degrading organic matter, such as kerogen, are described. A method for treating kerogen in a subterranean zone includes placing a composition in the subterranean zone, and the composition includes an oxidizer including sodium bromate and an additive including a tetrasubstituted ammonium salt.

Technologies relating to increasing hydraulic fracturing efficiencies in subterranean zones by degrading organic matter, such as kerogen, are described. A method for treating kerogen in a subterranean zone includes placing a composition in the subterranean zone, and the composition includes an oxidizer including sodium bromate and an additive including a tetrasubstituted ammonium salt.

A rigid radiation reflector is fabricated from a powdered material transparent to light in a wavelength band extending from approximately 0.2 micrometers to at least 8 micrometers. The powdered material is dispersed in a liquid wherein the powdered material is at least 95% insoluble in the liquid. The resulting mixture is molded under pressure at room temperature and then sintered to generate a porous solid. The porous solid is cooled to room temperature. A surface of the porous solid is then coated with a light-reflecting metal.

A rigid radiation reflector is fabricated from a powdered material transparent to light in a wavelength band extending from approximately 0.2 micrometers to at least 8 micrometers. The powdered material is dispersed in a liquid wherein the powdered material is at least 95% insoluble in the liquid. The resulting mixture is molded under pressure at room temperature and then sintered to generate a porous solid. The porous solid is cooled to room temperature. A surface of the porous solid is then coated with a light-reflecting metal.

The invention belongs to the field of bromine recovery from waste circuit board, and particularly relates to a method for recovering high-purity sodium bromide from bromine-containing crude salt. The invention mainly includes the steps of acidification oxidation, multi-stage extraction, and cooperative back extraction. Compared with traditional chlorine oxidation and single urea back extraction technology, the acidification oxidation process can be effectively controlled by reasonable adjustment of the added amount of hydrochloric acid and sodium chlorate, and the tail gas can be absorbed and reused to avoid secondary pollution and resource waste. At the same time, urea is used with sodium carbonate for cooperative back extraction to achieve a high back extraction rate which greatly reduces the amount of urea, and obtains high-purity sodium bromide crystals. The efficient recovery of bromine resources in bromine-containing crude salt is realised. The benefits of the invention are: high product purity, simple operation, environmental friendliness.

The invention belongs to the field of bromine recovery from waste circuit board, and particularly relates to a method for recovering high-purity sodium bromide from bromine-containing crude salt. The invention mainly includes the steps of acidification oxidation, multi-stage extraction, and cooperative back extraction. Compared with traditional chlorine oxidation and single urea back extraction technology, the acidification oxidation process can be effectively controlled by reasonable adjustment of the added amount of hydrochloric acid and sodium chlorate, and the tail gas can be absorbed and reused to avoid secondary pollution and resource waste. At the same time, urea is used with sodium carbonate for cooperative back extraction to achieve a high back extraction rate which greatly reduces the amount of urea, and obtains high-purity sodium bromide crystals. The efficient recovery of bromine resources in bromine-containing crude salt is realised. The benefits of the invention are: high product purity, simple operation, environmental friendliness.

Provided is a method for producing an alkali metal halide, including causing a reaction of an alkali metal sulfide and a substance represented by the following general formula (1) in the absence of a solvent or in a solvent except for water: X.sub.2 (1), wherein X represents a halogen element.