TREATMENT of AURIFEROUS ORES.

Te Aroha News, Volume VI, Issue 311, 27 October 1888, Page 2

TREATMENT of AURIFEROUS ORES.

A London correspondent sayg : Professor William Croolcos lias patented some improvements in the treatment of auriferous ores, and has discovered a method of revivifying the materials employed so that they could again be utilised. By experiment he ascertained that it was possible to treat some samples of auriferous ores efficiently by the nso of commercial perchloride of iron, but that other ores required a different treatment (o prevent a large percentage of the gold from being lost in the tailings. The best results are obtained by subjecting crushed auriferous ores to the action of a solution of perchloride of iron, with or without common salt, in the presence of heat, either with the addition of nitrate of soda, nitrate of potash, or equivalent nitrate, or peroxide of manganese, or free mineral acid. The pulverised ores are passed into a large tank containing the chemical preparation in solution, After continually stirring the mass for some time, and heating the mixture to a high temperature, it is allowed to settle. Then the rlear liquor is drawn off, or the mixture clarified by filtration. The residue is washed, and the metals precipitated from the clear solution. It is declared that by means of this process refractory ores can be treated for 8s per ton ; while from 80 to 90 per cent of the j gold would be extracted. The three points to which Professor Crookes attaches the most importance, and which he has patented, are : 1. The use of peroxide of manganese in combination with perchloride of iron in the treatment of auriferous ores. 2. T'le use, as an oxidising agent, in the treatment of auriferous ores by perchloride of iron, of nitrate of soda, nitrate of potash, or some equivalent nitrate, alone or in combination with peroxide of manganese. 3, A plan for the revivification of spent chloride of iron.