A method for recovering lead oxide from a pre-desalted lead paste, comprising the following steps: a. dissolving the pre-desalted lead plaster by using a complexing agent solution, and making all of PbO therein react with the complexing agent to generate lead complexing ions, obtaining a lead-containing solution and a filter residue; b. adding a precipitant to the lead-containing solution, and then the precipitant reacting with the lead complexing ions to generate a lead salt precipitate and the regenerated complexing agent; c. calcining the lead salt precipitate to obtain lead oxide and regenerate the precipitant. The final recovery rate of lead oxide of the method can reach 99% or more.

A method of pretreatment and bromine recovery of PCB Incineration ash is disclosed that relates to the field of comprehensive recovery of valuable metals by full wet method, especially relates to a method of valuable metals and bromine recovery, precious metals enrichment in pretreatment process of PCB Incineration ash. The major steps includes alkali leaching, Cu extraction back-extraction, neutralization-precipitation to separate, Bromine evaporative crystallization, regeneration, acid pickling, Zn evaporative crystallization, removal of Zn and Cu. Compared with the traditional comprehensive recovery process of ash, the invention can separate bromine from ash and recover valuable metals such as copper, zinc and lead with the maximum extent, at the same time, the enrichment of silver and other precious metals is beneficial to the subsequent recovery of precious metals. It has high added recovery value and no tailless discharge.

Systems and methods for producing potassium sulfate. Such a method involves providing an industrial waste material that includes at least one metal sulfate or a metal product that has been reacted with sulfuric acid to produce metal sulfates, and then reacting the metal sulfate with potassium carbonate to produce a byproduct that contains potassium sulfate.

Systems and methods for producing potassium sulfate. Such a method involves providing an industrial waste material that includes at least one metal sulfate or a metal product that has been reacted with sulfuric acid to produce metal sulfates, and then reacting the metal sulfate with potassium carbonate to produce a byproduct that contains potassium sulfate.

A method of pretreatment and bromine recovery of PCB Incineration ash is disclosed that relates to the field of comprehensive recovery of valuable metals by full wet method, especially relates to a method of valuable metals and bromine recovery, precious metals enrichment in pretreatment process of PCB Incineration ash. The major steps includes alkali leaching, Cu extraction back-extraction, neutralization-precipitation to separate, Bromine evaporative crystallization, regeneration, acid pickling, Zn evaporative crystallization, removal of Zn and Cu. Compared with the traditional comprehensive recovery process of ash, the invention can separate bromine from ash and recover valuable metals such as copper, zinc and lead with the maximum extent, at the same time, the enrichment of silver and other precious metals is beneficial to the subsequent recovery of precious metals. It has high added recovery value and no tailless discharge.

Systems and methods for producing potassium sulfate. Such a method involves providing an industrial waste material that includes at least one metal sulfate or a metal product that has been reacted with sulfuric acid to produce metal sulfates, and then reacting the metal sulfate with potassium carbonate to produce a byproduct that contains potassium sulfate.

Systems and methods for producing potassium sulfate. Such a method involves providing an industrial waste material that includes at least one metal sulfate or a metal product that has been reacted with sulfuric acid to produce metal sulfates, and then reacting the metal sulfate with potassium carbonate to produce a byproduct that contains potassium sulfate.

The invention relates to a process for the treatment of a hydrocarbon-containing feedstock making it possible to obtain a heavy hydrocarbon-containing fraction having a low sulphur content, said process comprising the following stages: a) a stage of hydrodemetallization in permutable reactors b) a stage of fixed-bed hydrotreatment of the effluent originating from stage a), c) a stage of hydrocracking in permutable reactors of the effluent originating from stage b), d) a stage of separation of the effluent originating from stage c), e) a stage of precipitation of the sediments, f) a stage of physical separation of said sediments from the heavy liquid fraction originating from stage d), g) a stage of recovery of the distillate cut used in stage e).

Systems and processes for producing ammonium sulfate that include providing an industrial waste material that includes at least lead sulfate and sulfuric acid. Ammonium hydroxide is added to the industrial waste material to raise the pH thereof and react the sulfuric acid to produce ammonium sulfate, and the lead sulfate is reacted with ammonium carbonate to produce lead carbonate.

Systems and processes for producing ammonium sulfate that include providing an industrial waste material that includes at least lead sulfate and sulfuric acid. Ammonium hydroxide is added to the industrial waste material to raise the pH thereof and react the sulfuric acid to produce ammonium sulfate, and the lead sulfate is reacted with ammonium carbonate to produce lead carbonate.