Determination of polythionates and thiosulphate in mining effluents and mill circuit solutions

Monitoring polythionate bio-oxidation by conductivity measurement

“…The total concentration of polythionates was determined by the acidimetric method with mercury chloride (Makhija and Hitchen, 1978). Thiosulphate and sulphite ions were analysed through iodometry; discrimination between the two ions was achieved by masking the sulphite ion with formaldehyde (Kurtenacker and Bittner, 1924;KoH, 1990).…”

“…Although these methods are of relevance, the complexity between polythionates renders them inconclusive. The polythionate concentration is usually determined by the mercuric chloride acidimetric titration method (Makhija and Hitchen, 1978). This method involves quantifying the total amount of acid produced by polythionates, expressed as tetrathionate.…”

Experimental study of pyrite oxidation at pH 6-9 and 30 degrees C

“…These textures suggest that iron dissolution was at best incomplete, and thus the process differs fundamentally from that under acidic conditions. Also notable is the fact that sulfur intermediates in the pathway are reported during sulfide oxidation at higher pH's in contrast to whajt has been observed at low pH (Forward and Mackiw, 1955;Makhija and Hitchen, 1978). Although such intermediates have been noted, there has been no systematic laboratory study of the conditions of production of such intermediates that can be related to uranium deposition.…”

Chemical Oxidation Methods for the Treatment of Thiosalt-Containing Mill Effluents

“…Bench-scale experiments were conducted to explore possible process parameters, and to elucidate some of the chemistry involved. [12]. The results were expressed in thiosulphate equivalents (SZ03) and the stoichiometric relationships are listed in Table 2.…”