Gte Laboratories Incorporated

Gte Products Corporation

William J Rourke

Samuel Natansohn

Wen-Chao Lai

A process for treating a sludge comprises digesting the waste material with a mixture of sulfuric acid and hydrogen peroxide to form an acidic digestion solution and a digestion residue. The digestion residue containing the major portion of tungsten and other refractory metals is reacted with NaOH to solubilize the major portion of tungsten values to a liquid concentrate that is separated from the insoluble solid that contains the major portion of the other refractory metals such as tantalum and niobium. The digestion solution containing the major portion of the transition and rare metals is treated with a base to selectively recover iron as a solid iron hydroxide precipitate which is separated from the resulting liquor. The liquor is then treated again with a base to selectively recover the other metals such as Sc, Cr, rare earths, but not Mn, as a solid metal hydroxide precipitate that is separated from the solution. The resulting solution containing the major portion of Mn is treated with a base to a pH of about 9.5 under an oxidative environment to recover manganese as a solid manganese hydroxide precipitate that is separated from the solution. The final waste effluent at a pH of 9.5 can be used for its alkali values and for diluting the concentrated acidic solution from the initial digestion of the waste materials.

Treatment of industrial wastes

A process is disclosed for purifying scandium from an acid solution containing scandium and various impurities. The process involves mixing the acid solution with a chelating resin in the hydrogen form to from a slurry and packing the slurry in a short ion exchange column. The ion exchange column is rinsed with a mineral acid and the scandium is removed by passing diglycolic acid through the column. The diglycolic acid containing scandium is then passed through a chelating resin in the H form. When the scandium concentration in the effluent from the chelating resin reaches a preselected level the effluent of digylcolic acid and scandium is collected. Collection is stopped when the scandium concentration in the eluent falls below a preselected level. This collected eluent is passed through a strong cation exchange column where the scandium is collected. After rinsing the strong cation exchange column with deionized water, the scandium is removed from the column by passing a solution of ammonium nitrate through the strong cation exchange resin. The scandium is precipated from the ammonium nitrate by adding oxalic acid. The precipate of scandium oxalate is collected by filtration and rinsed. The precipate is calcined at approximately 975.degree. C. to form scandium oxide. This process is applicable to the recovery and purification of scandium from any acid soluble matrix.

Ion exchange method for the purification of scandium

A process for eliminating an industrial waste sludge by converting its metal values into useful products involves the selective leaching of Mn, divalent Fe, and other valuable metals, such as Sc, Co, Cr, Ni, Th, rare earths, etc. with a mixture of dilute sulfuric acid and a reductant at ambient temperature. Scandium is recovered by passing the leachate through an ion exchange column which is packed with a weakly cationic resin. The retention of other metals on the resin column is negligible. The scandium is eluted from the resin column and converted to a solid product. The raffinate from the ion exchange column is titrated with an alkali solution to convert the metals, except divalent Mn and Fe, to a solid metal hydroxide. After the separation the filtrate is treated with an alkali and an oxidant to recover iron as a solid product of iron oxide which is separated from the solution. The remaining solution contains only Mn values which are recovered by treating the solution with an alkali and an oxidant to yield a solid manganese product. Separation of the solid leaves a liquid that can be discharged directly. The residue from the initial acid leaching contains the remaining metal values. HCl is used to selectively dissolve the Fe values. The insoluble residue is digested in an alkali to extract the total tungsten values. The residue from the alkali digestion contains substantial amounts of Ta, Nb and Ti and is a viable source for these metals.

Process for recovering metal values such as scandium, iron and manganese

Bracket

The separation of uranium, iron and scandium is achieved by the following process wherein a material containing these values is dissolved in mineral acid to form an aqueous solution, thereafter, an iminodiacetic acid cationic ion exchange resin is used to retain a major portion of the scandium and uranium. A raffinate containing the iron is formed. The ion exchange resin having said scandium and uranium retained thereon is rinsed with a dilute acid to remove residual metals other than scandium and uranium. The resin is eluted with an aqueous solution of an organic chelating acid to remove a major portion of the scandium from said resin and to form an aqueous solution containing scandium. The resin is then eluted with an aqueous solution of a mineral acid to remove a major portion of the uranium from the resin to form an aqueous solution containing the uranium. The scandium and uranium are recovered as solids.

Recovery of scandium and uranium

A process for recovering the scandium present as a trace constituent in a mixture of iron, manganese and other oxides comprise bringing the scandium into solution along with much of the other base metals, reducing the dissolved iron to the ferrous state, adjusting the pH of the resulting solution to a value of about 2.0 and selectively extracting the scandium with an organic extractant consisting of thenoyltrifluoroacetone dissolved in an aromatic solvent. The scandium values are recovered quantitatively from the organic extractant by treating it with a dilute acid. The process effects a complete separation of the scandium from the base metals resulting in a scandium product of high purity.

Liquid extraction procedure for the recovery of scandium

Combined bracket and trash bag support for a post-mounted tray

A method of recovering quantitatively trace amounts of scandium from aqueous solutions containing large amounts of other metals consists of reducing any manganese and iron in the solution to the divalent states of manganese and iron. The solution is then adjusted to a pH from about 1.9 to about 2.1 and passed through a column of the ion exchange resin in the hydrogen form having an iminodiacetic acid functionality. The scandium is absorbed on the column and any base metals and rare earth metals which were also absorbed are removed by eluting with a dilute acid without removing the scandium. The scandium is subsequently removed from the column by eluting with a solution containing a chelating agent such as diglycolic acid. The scandium is then recovered from the solution by precipitation, filtering, washing, drying and calcined to the oxide.

Ion exchange method for the recovery of scandium

A method for a quantitative separation of scandium from thorium comprises adsorption of both metals on a cation exchange resin followed by selective elution of scandium with an acidic solution of a chelating agent followed by the elution of thorium by a six normal hydrochloric acid solution.

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Worcester, MA, United States of America

William J Rourke