Cyanide heap leaching is the predominant technology used in processing low-grade gold ores. During closure of a heap leach operation, residual cyanide must be removed from the process and waste solutions, as well as the heap. Biological cyanide oxidation is a proven, economical technology for destroying cyanide in process and waste waters and spent heaps. The use of biological cyanide degradati...

CONTEXT Prussian blue, ferric hexacyanoferrate is approved for (oral) treatment of internal contamination with radioisotopes of cesium or thallium. Cyanide makes up 35-40% of Prussian blue's molecular composition; thus, cyanide may be released during transit through the digestive tract under physiological pH conditions. OBJECTIVES The purpose of this study is to assess the long-term stability...

The orthogonal array design has been used to determine the optimum conditions for gold recovery from Zarshuran refractory gold sulfide ore (Iran) by direct cyanidation and roasting-cyanidation. The Taguchi method was used as the experimental design to determine the optimum conditions of dissolution behavior of gold with cyanidation and roasting-cyanidation from Zarshuran refractory gold ore . T...

In the course of studies involving the reduction of ferricytochrome c by the succinic dehydrogenase system, it was observed that in the presence of cyanide there is a progressive decrease in the amount of reducible eytochrome c. This action of cyanide on cytochrome c had previously been reported by Pott.er (l), together with other evidence indicating the formation of a ferricytochrome c-cyanide...

The effect of cyanide on the physiology of lactateand oxygen-limited Enterobacter aerogenes NCTC 10336 was studied in chemostat culture ( D = 0.1 h-l). In the absence of cyanide, the molar growth yield from oxygen ( Yo2) under oxygen limitation was 60% of the carbon-limited value. A similar decrease in yield was observed in a lactate-limited culture (excess oxygen) which was continuously fed lo...

Twenty-six patients, receiving an infusion of sodium nitroprusside (SNP) during surgery, had considerable increases in both red cell and plasma cyanide concentration, but only small changes in plasma thiocyanate concentration. There was a linear relationship between both plasma and RBC cyanide concentrations and the total dose of SNP. The expired cyanide concentration followed the changes in th...

In this study, a rapid flow injection-flame atomic absorption spectrometry for cyanide detection was developed. Different AgX (where X is Cl(-), Br(-), I(-) and N(3)(-)) solid-phase reagents (SPR) were tested for indirect determination of cyanide. In a single-line FIA system, the cyanide was allowed to react with AgX SPR, which in turn changed Ag ions in AgX to silver cyanide complexes in a sod...

Near-infrared light via light-emitting diode treatment has documented therapeutic effects on neurons functionally inactivated by tetrodotoxin or methanol intoxication. Light-emitting diode pretreatment also reduced potassium cyanide-induced cell death, but the mode of death via the apoptotic or necrotic pathway was unclear. The current study tested our hypothesis that light-emitting diode rescu...

Cyanide inhibits aerobic metabolism by binding to the binuclear heme center of cytochrome c oxidase (CcOX). Amyl nitrite and sodium nitrite (NaNO(2)) antagonize cyanide toxicity in part by oxidizing hemoglobin to methemoglobin (mHb), which then scavenges cyanide. mHb generation is thought to be a primary mechanism by which the NO(2)(-) ion antagonizes cyanide. On the other hand, NO(2)(-) can un...

Methods of directly evaluating cyanide levels are limited by the volatility of cyanide and by the difficulty of establishing steady-state cyanide levels with time. We investigated the measurement of a stable, toxic metabolite, 2-aminothiazoline-4-carboxylic acid (ATCA), in an attempt to circumvent the challenge of directly determining cyanide concentrations in aqueous media. This study was focu...