Methods treat ash from waste incineration, wherein the methods at least comprise: a) the digestion of the ash by a leaching liquor containing phosphate ions in solution such as to form a first solid phase comprising impurities and a first liquid phase comprising phosphate ions; and b) the separation of said first liquid phase comprising phosphate ions from said first solid phase. Step a) is carried out for a duration of less than one hour or at a temperature of more than 40 C.

In one aspect, the disclosure relates to a microwave-assisted comminution method for achieving more efficient beneficiation and later hydrometallurgical recovery of rare earth elements and other metals from coal fly ash particles. The method requires only a short processing time, is energy efficient, allows for better process control, and is environmentally advantageous compared to current methods. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

In one aspect, the disclosure relates to a microwave-assisted comminution method for achieving more efficient beneficiation and later hydrometallurgical recovery of rare earth elements and other metals from coal fly ash particles. The method requires only a short processing time, is energy efficient, allows for better process control, and is environmentally advantageous compared to current methods. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

The present disclosure relates to a method for removing halide from halide-containing Waelz oxide. According to the method, it is possible to effectively remove halide contained in Waelz oxide, especially insoluble fluoride such as CaF.sub.2, which are difficult to remove under atmospheric pressure conditions and present as insoluble substances. Accordingly, in the process of recovering valuable metals, an additional process for adjusting the concentration of fluorine or chlorine present in the electrolyte can be omitted, and costs can be reduced.

The present disclosure relates to a method for removing halide from halide-containing Waelz oxide. According to the method, it is possible to effectively remove halide contained in Waelz oxide, especially insoluble fluoride such as CaF.sub.2, which are difficult to remove under atmospheric pressure conditions and present as insoluble substances. Accordingly, in the process of recovering valuable metals, an additional process for adjusting the concentration of fluorine or chlorine present in the electrolyte can be omitted, and costs can be reduced.

This invention refers to a process for the production of products in the form of commercial zinc oxide and iron ecosinter, which are important raw materials for the production of SHG zinc (a special quality product) and pig iron, with subsequent obtaining steel. The process for producing zinc oxide concentrate and iron ecosinter uses as raw material zinc ferrite residues, steelmaking co-products such as light mud, heavy mud, iron scale, pre-lime and yard cleaning materials rich in iron and, mainly, steel mill dust (class I) mixed with carbon sources, whose mixture is homogenized and pelletized, followed by reduction in a pot furnace fed by insufflated air in ascending flow with temperature ranging from 850 C. to 1,300 C.; being the volatilized metals and the gases generated sent to a cyclone and bag filter where the zinc oxide is retained; the iron ecosinter is poured from the pot at the end of the process.

A zinc production method includes a reaction step such as a leaching step (101) of bringing electric arc furnace dust (1) containing zinc oxide or the like into contact with a chlorine gas (8) to obtain a zinc oxide component in the electric arc furnace dust (1) or the like as crude zinc chloride (3), a purification step (102) of heating the crude zinc chloride (3) obtained at the reaction step to produce zinc chloride vapor, and cooling and condensing the zinc chloride vapor, thereby obtaining purified zinc chloride (6), and an electrolysis step (103) of electrolyzing the purified zinc chloride (6) obtained at the purification step (102) in a molten state to obtain a zinc melt (9) and the chlorine gas (8).

A zinc production method includes a reaction step such as a leaching step (101) of bringing electric arc furnace dust (1) containing zinc oxide or the like into contact with a chlorine gas (8) to obtain a zinc oxide component in the electric arc furnace dust (1) or the like as crude zinc chloride (3), a purification step (102) of heating the crude zinc chloride (3) obtained at the reaction step to produce zinc chloride vapor, and cooling and condensing the zinc chloride vapor, thereby obtaining purified zinc chloride (6), and an electrolysis step (103) of electrolyzing the purified zinc chloride (6) obtained at the purification step (102) in a molten state to obtain a zinc melt (9) and the chlorine gas (8).

A process is described for recovering a non-ferrous metal from a first solid residue comprising iron. In this process, the first solid residue is mixed with a second solid residue including sulphur, thereby obtaining a particulate mixture. The particulate mixture is subjected to a roasting step at a temperature of at least 650 C. to obtain a roasted mixture, and the roasted mixture is subjected to leaching in a liquid at a pH of at least 5.5 to obtain a solution enriched with the non-ferrous metal.

A process is described for recovering a non-ferrous metal from a first solid residue comprising iron. In this process, the first solid residue is mixed with a second solid residue including sulphur, thereby obtaining a particulate mixture. The particulate mixture is subjected to a roasting step at a temperature of at least 650 C. to obtain a roasted mixture, and the roasted mixture is subjected to leaching in a liquid at a pH of at least 5.5 to obtain a solution enriched with the non-ferrous metal.