A method for recovering lithium from a lithium-containing solution is provided. A lithium-containing solution with an adjusted pH value or an unadjusted pH value is mixed with a meta-aluminate, and the pH value is adjusted to weak acid/neutral, so that lithium can be separated from the lithium-containing solution in the form of a precipitate of Li.sub.aX.Math.2Al(OH).sub.3.Math.nH.sub.2O. Then, the precipitate is converted into a lithium adsorbent of (1-m)Li.sub.aX.Math.2Al(OH).sub.3.Math.nH.sub.2O and a Li.sub.aX-containing filtrate through desorption of lithium. High-purity Li.sub.2CO.sub.3 is obtained by performing precipitation of lithium on the Li.sub.aX-containing filtrate.

Compositions, systems, and methods for selectively leaching and/or extracting lithium from sedimentary deposits and other resources are generally described.

A method for extracting noble metals from mining tailings and other solids is provided. The method uses a Lewis acid, Brønsted acid, complexing agent and oxygen to provide excellent extraction without the need for chorine gas or cyanide.

Methods for recovering a metal from a metal-containing material are provided. In embodiments, such a method comprises exposing a metal-containing material to a leaching solution comprising a solvent and a binoxalate, a tetraoxalate, or a combination thereof, under conditions to provide a leachate comprising a soluble metal oxalate; inducing precipitation of a metal-containing precipitate comprising the metal of the soluble metal oxalate from the leachate; and recovering the metal-containing precipitate.

A system for producing a magnesium chloride aqueous solution includes a crystallization unit configured to generate reaction slurry in which particles of magnesium hydroxide are dispersed by adding a sodium hydroxide aqueous solution to water to be treated, a precipitation unit configured to store reaction slurry, precipitate particles and separate the reaction slurry into recovered slurry and a separated liquid, a removal unit configured to remove divalent cations from the water to be treated or the separated liquid to generate a reaction liquid, an acid-alkali generation unit configured to generate a sodium hydroxide aqueous solution and hydrochloric acid from the reaction liquid, and a reaction unit configured to generate a magnesium chloride aqueous solution by adding hydrochloric acid to the recovered slurry. The acid-alkali generation unit has a main body section configured to generate a sodium hydroxide aqueous solution and hydrochloric acid from the reaction liquid.

A method for separating thorium and cerium from a solid concentrate comprising compounds of thorium, cerium and further rare earth metals, comprising: a) contacting the solid concentrate with an acid to achieve an acid composition with a pH of less than 0.5; b) reacting the acid composition obtained in step a) with ozone or heating the acid composition at a temperature ranging from 110° C. to 130° C. for a time period ranging from 1 to 3 hours, thereby oxidizing the cerium ions in the acid composition to an oxidation state of +IV; c) increasing, to at most 2, the pH of the composition obtained in step b), resulting in the precipitation of thorium and cerium compounds; and d) separating the precipitated thorium and cerium compounds from the composition obtained in step c) to obtain an aqueous acidic rare earth solution depleted in thorium and cerium.

The invention relates to a method for recovering precious metals from electronic waste utilising biometallurgical techniques. In one aspect, a method of recovering one or more target metals from electronic waste, includes (a) removing at least a portion of non-target material from the electronic waste or grinding to a preselected size particle to give pre-processed electronic waste; (b) contacting the pre-processed electronic waste with a lixiviant such that at least a portion of the target metal(s) dissolve into the lixiviant to produce a pregnant solution; (c) contacting a microorganism with the pregnant solution such that at least a portion of the target metal(s) ions biosorb to the microorganism wherein the microorganism becomes metal laden and the pregnant solution becomes barren; (d) substantially separating the metal laden microorganism from the barren solution; and (e) recovery of the target metal(s) from the metal laden microorganism.

The invention relates to hydrometallurgical method for recovering lithium and one or more transition metals from spent lithium ion batteries, comprising: treating an electrode material of the batteries in an alkaline solution to dissolve lithium in said solution; separating from the alkaline solution a solid phase consisting of lithium-depleted electrode material; recovering lithium from said alkaline solution; leaching the lithium-depleted electrode material with an acid leach solution to dissolve one or more transition metals of the electrode material in the leach solution; separating insoluble material, if present, from the leach solution to obtain metal-bearing aqueous solution and isolating one or more transition metal(s) and optionally the remainder of the lithium from said metal-bearing aqueous solution.

A method for recovering metals from waste materials includes steps of contacting a waste material feed stream with a first lixiviant adapted to leach copper and other base metals from the waste material feed stream and provide a treated waste material feed stream, recovering copper metal from the first lixiviant, contacting the treated waste material stream with a second lixiviant adapted to leach noble metals from the treated waste material feed stream and recovering gold from the second lixiviant.

A method of treating a waste liquid: an aluminum dissolution step of dissolving aluminum in an acidic waste liquid and performing separation into a first treated water and a reduced heavy metal precipitate; a gypsum recovery step of adding a calcium compound to the first treated water at a pH of 4 or less, and performing separation into a second treated water and gypsum; a heavy metal coprecipitation step of adding a ferric compound to the second treated water and performing separation into a third treated water and a heavy metal coprecipitate; an aluminum and fluorine removal step of adding an alkali to the third treated water and performing separation into a fourth treated water and a precipitate containing aluminum and fluorine; and a neutralization step of adding an alkali to the fourth treated water and performing separation into an alkali neutralization treated water and a neutralized heavy metal hydroxide.