This invention relates to treated geothermal brine compositions containing reduced concentrations of lithium, iron and silica compared to the untreated brines. Exemplary compositions contain concentration of lithium ranges from 0 to 200 mg/kg, concentration of silica ranges from 0 to 30 mg/kg, concentration of iron ranges from 0 to 300 mg/kg. Exemplary compositions also contain reduced concentrations of elements like arsenic, barium, and lead.

This invention relates to treated geothermal brine compositions containing reduced concentrations of lithium, iron and silica compared to the untreated brines. Exemplary compositions contain concentration of lithium ranges from 0 to 200 mg/kg, concentration of silica ranges from 0 to 30 mg/kg, concentration of iron ranges from 0 to 300 mg/kg. Exemplary compositions also contain reduced concentrations of elements like arsenic, barium, and lead.

This invention relates to a process for recovering valuable metals from ore with significantly reduced water consumption through the discrete treatment and storage of coarse tailings. Ore is ground to produce a coarse particulate ore. The coarse particulate ore is treated in a coarse flotation stage to produce a low grade concentrate fraction and a coarse tailings fraction. The low grade concentrate fraction is treated to produce fine tailings and a saleable concentrate. The coarse tailings are treated separately from the fine tailings and water is recovered from the coarse tailings by hydraulically stacking; filtering or screening, whereafter the coarse tailings are dry stacked, without being recombined with the fine tailings.

This invention relates to a process for recovering valuable metals from ore with significantly reduced water consumption through the discrete treatment and storage of coarse tailings. Ore is ground to produce a coarse particulate ore. The coarse particulate ore is treated in a coarse flotation stage to produce a low grade concentrate fraction and a coarse tailings fraction. The low grade concentrate fraction is treated to produce fine tailings and a saleable concentrate. The coarse tailings are treated separately from the fine tailings and water is recovered from the coarse tailings by hydraulically stacking; filtering or screening, whereafter the coarse tailings are dry stacked, without being recombined with the fine tailings.

The invention relates to a method for concentrating metals, in particular silver and/or tin and/or lead from scrap containing metal, by treating the material/scrap containing silver and/or tin and/or lead with a sulfonic acid of the formula RSO.sub.2OH in the presence of an oxidizing agent, wherein R can be an organic group or ammonia.

A stabilization process for an arsenic solution comprising thiosulfates, the process comprising: acidifying the arsenic solution to decompose the thiosulfates, to yield an acidified solution; oxidizing the acidified solution to oxidize residual As.sup.3+ to As.sup.5+ and reduced sulfur species to sulfates, to yield a slurry comprising elemental sulfur; separating elemental sulfur from the slurry to yield a liquid; oxidizing the liquid to oxidize residual reduced sulfur species, to yield an oxidized solution; and forming a stable arsenic compound from the oxidized solution.

A stabilization process for an arsenic solution comprising thiosulfates, the process comprising: acidifying the arsenic solution to decompose the thiosulfates, to yield an acidified solution; oxidizing the acidified solution to oxidize residual As.sup.3+ to As.sup.5+ and reduced sulfur species to sulfates, to yield a slurry comprising elemental sulfur; separating elemental sulfur from the slurry to yield a liquid; oxidizing the liquid to oxidize residual reduced sulfur species, to yield an oxidized solution; and forming a stable arsenic compound from the oxidized solution.

A process for recovering non-ferrous metals from a solid matrix may include: leaching the solid matrix with an aqueous-based solution, in a presence of oxygen, to obtain an extraction solution including leached metals and solid leaching residue; separating the solid leaching residue from the extraction solution; and subjecting the extraction solution to at least one cementation to recover the leached metals in elemental state. The leaching solution may include chloride ions. The leaching solution may further include ammonium ions. A pH of the leaching solution may be greater than or equal to 6.5 and less than or equal to 8.5. A leaching temperature may be greater than or equal to 100 C. and less than or equal to 160 C. A leaching pressure may be greater than or equal to 150 kPa and less than or equal to 800 kPa.

A process is provided for separation of at least one metal sulfide from a mixed sulfide concentrate. The process includes: subjecting the mixed sulfide concentrate to flotation in which at least one sulfide including antimony, arsenic and a first metal is floated and at least one sulfide including a second metal is depressed. The flotation yields a first metal concentrate having the at least one sulfide including antimony, arsenic and the first metal and a second metal concentrate having the at least one sulfide including the second metal. The first metal concentrate is leached to yield a further concentrate and a leach solution. The further concentrate includes the first metal and the leach solution includes soluble antimony and soluble arsenic. The process further includes oxidizing the leach solution to yield an antimony precipitate and an arsenic solution, and forming a stable arsenic compound from the arsenic solution.

A process is provided for separation of at least one metal sulfide from a mixed sulfide concentrate. The process includes: subjecting the mixed sulfide concentrate to flotation in which at least one sulfide including antimony, arsenic and a first metal is floated and at least one sulfide including a second metal is depressed. The flotation yields a first metal concentrate having the at least one sulfide including antimony, arsenic and the first metal and a second metal concentrate having the at least one sulfide including the second metal. The first metal concentrate is leached to yield a further concentrate and a leach solution. The further concentrate includes the first metal and the leach solution includes soluble antimony and soluble arsenic. The process further includes oxidizing the leach solution to yield an antimony precipitate and an arsenic solution, and forming a stable arsenic compound from the arsenic solution.