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Malononitrile Extraction of Gold from Ores.

PB196691

Publication Date	1970
Personal Author	Heinen, H. J.; Eisele, J. A.; Scheiner, B. J.
Page Count	15
Abstract	Malononitrile (CH2 (CN)2), which forms a carbanion in basic solutions, was investigated as a potential leachant for gold and was shown to be an effective extractant in alkaline pulps. Malononitrile was comparable to equal molar quantities of sodium cyanide (NaCN) in leaching gold from an oxide ore and yielded 10 to 20 percent higher recovery in leaching a refractory carbonaceous ore, although dissolution was slower with malononitrile than with cyanide. Complete recovery of the gold from the pregnant solutions was achieved by coprecipitation with a lead salt on zinc dust; the leachant was shown to be capable of regeneration and recycling a limited number of times. Addition of an anion-exchange resin to the carbonaceous pulp containing malononitrile increased gold recovery from 67 to 95 percent. Some malononitrile derivatives were also shown to be gold solvents. (Author)
Keywords	Metalliferous minerals Extractive metallurgy Leaching Gold Benefication Nitriles Organic solvents Anion exchanging Precipitation(Chemistry) Solvent extraction Malononitriles
Source Agency	Invalid Source Agency Code
NTIS Subject Category	48A - Mineral Industries
Corporate Authors	BUREAU OF Mines, Washington, D.C.
Document Type	Technical Report
Title Note	Rept. of investigations.
NTIS Issue Number	197105

Malononitrile Extraction of Gold from Ores.

Malononitrile Extraction of Gold from Ores.
PB196691

Publication Date	1970
Personal Author	Heinen, H. J.; Eisele, J. A.; Scheiner, B. J.
Page Count	15
Abstract	Malononitrile (CH2 (CN)2), which forms a carbanion in basic solutions, was investigated as a potential leachant for gold and was shown to be an effective extractant in alkaline pulps. Malononitrile was comparable to equal molar quantities of sodium cyanide (NaCN) in leaching gold from an oxide ore and yielded 10 to 20 percent higher recovery in leaching a refractory carbonaceous ore, although dissolution was slower with malononitrile than with cyanide. Complete recovery of the gold from the pregnant solutions was achieved by coprecipitation with a lead salt on zinc dust; the leachant was shown to be capable of regeneration and recycling a limited number of times. Addition of an anion-exchange resin to the carbonaceous pulp containing malononitrile increased gold recovery from 67 to 95 percent. Some malononitrile derivatives were also shown to be gold solvents. (Author)
Keywords	Metalliferous minerals Extractive metallurgy Leaching Gold Benefication Nitriles Organic solvents Anion exchanging Precipitation(Chemistry) Solvent extraction Malononitriles
Source Agency	Invalid Source Agency Code
NTIS Subject Category	48A - Mineral Industries
Corporate Authors	BUREAU OF Mines, Washington, D.C.
Document Type	Technical Report
Title Note	Rept. of investigations.
NTIS Issue Number	197105