Abstract: The invention is an apparatus and process for recovering metal from a solution. This apparatus is a structure having an anode formed from a plurality of reducing metal elements and a cathode formed from a high surface area electrically conductive material such as metal wire. The reducing metal elements of the anode have a more negative standard state reduction potential than the metal to be recovered. This invention is also a process in which a metal is recovered by contacting a solution of a metal to be recovered with the apparatus of the invention.

Abstract: An improved process for recovery for precious metals such as gold and silver from aqueous cyanide solutions by contact with certain guanidine reagents. The guanidine reagents not only extract the precious metal but may provide advantages in selectivity of gold over other metals, such as tetra- and pentahydrocarbon substituted non-resin guanidine reagents and tri- and tetra-hydrocarbon substituted resin guanidine reagents.

Abstract: Recovery of precious metals such as gold and silver from aqueous cyanide solutions thereof, by contact with a reagent containing a guanidine functionality. The guanidine reagent extracts the precious metal from the aqueous solution which is subsequentily stripped from the guanidine reagent and recovered by conventional methods. Certain novel guanidine compounds suitable for extracting gold and silver are disclosed.

Abstract: Disclosed is a process for recovery of amino acids from aqueous mixtures. In particular, it relates to a treatment of said amino acid containing aqueous mixture prior to extraction of the amino acid with a water immiscible organic solution containing a water insoluble extractant for said amino acid. The overall process of the invention which includes the pretreatment and extraction, also includes optional methods of recovering said extracted amino acid from the water immiscible organic solution. Accordingly, the invention also relates to a process for recovery of the amino acid by stripping of the amino acid from the organic solution and precipitation of the amino acid.

Abstract: An improvement in the process of extraction of amino acids from aqueous solutions in which the amino acids are extracted with quaternary ammonium extractants. A pretreatment of the amino acid containing aqueous solution with a tertiary amine prior to extraction of the amino acids with the quaternary ammonium extractant, removes some impurities or poisons present therein, leaving the amino acids in the aqueous solution for subsequent extraction with a water insoluble quaternary ammonium extractant. After extraction with the quaternary extractant, the organic phase is stripped of amino acid and the stripped organic is subjected to an acidic scrub before returning to the quaternary extraction stage.

Abstract: Recovery of precious metals such as gold and silver from aqueous cyanide solutions thereof, by contact with a reagent containing a guanidine functionality. The guanidine reagent extracts the precious metal from the aqueous solution which is subsequently stripped from the guanidine reagent and recovered by conventional methods. Certain novel guanidine compounds suitable for extracting gold and silver are disclosed.

Abstract: Amino acids can be purpified and/or concentrated by extracting aqueous mixtures such as fermentation broths by contacting an aqueous mixture containing amino acids with an organic solution containing a water insoluble extractant selected from the group consisting of:1. A quaternary ammonium ion having the formula: ##STR1## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are aliphatic, each having from 1 to 22 carbon atoms, and together have a minimum of 25 carbon atoms, and where at least three of the four R groups are at least a C.sub.4.2. A quaternary phosphonium ion having the formula: ##STR2## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are as defined above. 3. A tertiary sulfonium ion having the formula: ##STR3## where R.sub.1, R.sub.2 and R.sub.3 each are aliphatic with from 1 to 22 carbon atoms, and together have a minimum of 24 carbons and where at least two of these groups are at least a C.sub.6.4. An organic boride ion having the formula: ##STR4## where R.sub.1, R.sub.2, R.sub.3 and R.sub.

Abstract: Disclosed is a process for recovery of amino acids from aqueous mixtures. In particular, it relates to a treatment of said amino acid containing aqueous mixture prior to extraction of the amino acid with a water immiscible organic solution containing a water insoluble extractant for said amino acid. The overall process of the invention which includes the pretreatment and extraction, also includes optional methods of recovering said extracted amino acid from the water immiscible organic solution. Accordingly, the invention also relates to a process for recovery of the amino acid by stripping of the amino acid from the organic solution and precipitation of the amino acid.

Abstract: Recovery of precious metals such as gold and silver from aqueous cyanide solutions thereof, by contact with a reagent containing a guanidine functionality. The guanidine reagent extracts the precious metal from the aqueous solution which is subsequently stripped from the guanidine reagent and recovered by conventional methods. Certain novel guanidine compounds suitable for extracting gold and silver are disclosed.

Abstract: Substituted 8-hydroxyquinoline metal extractants having a cyclic hydrocarbon substituent at either the 5 and 7 or only the 7 position are described.

Abstract: Amino acids can be purified and/or concentrated by extracting aqueous mixtures such as fermentation broths by contacting an aqueous mixture containing amino acids with an organic solution containing a water insoluble extractant.

Abstract: An improvement in the process for preparing hydroxyarylaldehydes is disclosed where a phenolic compound is reacted with formaldehyde, in the presence of a catalyst such as a titanium or zirconium containing catalyst, optionally in the presence of a catalyst promoter, wherein the improvement is the addition of a yield effective amount of a modifier having the formula: ##STR1## where R.sub.1 is selected from the group consisting of: an alkyl group having from 1 to 12 carbon atoms, a cycloalkyl group that can have 5 and 6 carbon atoms, and an H, and where R.sub.2 is selected from the group consisting of: an alkyl group having from 1 to 12 carbon atoms, and a cyclo alkyl group that can have 5 to 6 carbon atoms; and where R.sub.1 and R.sub.2 can together form a cyclic group that can have 5 and 6 carbon atoms.

Abstract: Compounds of the structure ##STR1## where X is Cl or Br, R is a branched chain alkyl or alkenylradical containing about 8 to 20 carbon atoms and R.sub.1, R.sub.2 and R.sub.3 are hydrogen or alkyl groups of 1 to 4 carbon atoms. The new compounds find use in extraction of metals.

Abstract: Certain 2-hydroxy benzophenoximes containing an electron withdrawing substituent(s). Compositions comprised of such benzophenoximes and certain .alpha.-hydroxy aliphatic oximes. Compounds and compositions are useful for the extraction of metal values.