RU2386708C2 - Gold extraction method - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention refers to precious metal metallurgy and can be used for industrial gold extraction. Extraction method of gold from concentrate involves cyanidation or supply of chlorine-air mixture thus obtaining cyanide or muriatic gold-containing solutions respectively. Gold is extracted from the obtained solutions by sorption or carbonisation. At that, initial raw material is concentrate of phosphorite ore of shelly type of the Baltic-Ladogian gold field.

EFFECT: enlarging deposits of mineral raw material for industrial gold extraction.

1 ex

Description

The invention relates to the field of metallurgy of precious metals and mainly can be used for industrial gold.

For industrial extraction of gold are known (Strizhko L.S. Metallurgy of gold and silver: a Textbook for universities. - M .: MISIS, 2001, p. 27-35. The practice of processing gold ores using cyanide / Zelenov VI, Baryshnikov IF, Shtryneva EM - M .: Central Scientific Research Institute of Information and Technical and Economic Studies of Non-Ferrous Metallurgy, 1968, pp. 3-13. Zyryanov MN, Leonov SB Chloride Gold Metallurgy . - M .: SP INTERMET ENGINEERING, 1997, p.174-204. Lodeishchikov VV Technology for the extraction of gold and silver from refractory ores. Volume 1. - Irkut sk, OAO Irgiredmet, 1999, pp. 59-74. Lodeishchikov VV Technology for the extraction of gold and silver from refractory ores Volume 2. - Irkutsk, OAO Irgiredmet, 1999, pp. 517-713. RU 2275437 , 2006. RU 2268317, 2006. RU 2268318, 2006. RU 2261928, 2005. RU 2256712, 2005. RU 2235602, 2004. RU 2234544, 2004. RU 2149709, 2000. RU 2149707, 2000. RU 2149706. 2000. RU 2133644 , 2000. RU 2124573, 1999. RU 2109825, 1998. RU 2095449, 1997. RU 2089637, 1997. RU 2086682, 1997. RU 2065503, 1996. RU 2064512, 1996. RU 2040586, 1995. RU 2034062, 1995) gold, gold-pyrite, gold-quartz, gold-arsenic, gold-copper, gold-antimony, gold-uranium and gold-polymetallic ores, as well as their concentrates, cinder from ore roasting or concentrate and tailings flotation or gravity ore dressing.

A known method of extracting gold from gold ore concentrates of various deposits, including cyanide or supplying a chlorine-air mixture, obtaining cyanide and hydrochloric acid gold-containing solutions, respectively, and extracting gold from them by sorption or cementation (Lodeishchikov V.V. Technique and technology for extracting gold from ores abroad, M .: Metallurgy, 1973, p.5, 12, 246-252, 162-164) (the closest analogue).

The objective of the present invention is to expand the arsenal of minerals for industrial extraction of gold.

The problem is solved in that the extraction is carried out by the method [1] from a concentrate of phosphorite ore of shell rock type of the Baltic-Ladoga basin.

Phosphorite ores have been known since the mid-19th century from the work of J. Liebig (Die Organische Chemie in ihrer Anwendung auf Agricultur und Physiologic. - Munchen, 1840) and contain calcium phosphate as a useful component, which determines the traditional use of phosphate ores as raw materials for industrial production phosphoric acid, the waste of which is phosphoric flour, used as a mineral fertilizer. Currently, there are distinguished sedimentary phosphorite ores of granular, microgranular, nodule and shell rock types (Bushinsky GI Petrography of phosphorites of the Western region. In collection: Agrochemical ores of the USSR, v.3, part 11, 1934, p.154-201) . Calcium phosphate of the phosphorite ore of the shell type was formed as a result of the vital activity of ancient living organisms from their hard tissues, such as shells, bones and teeth. At present, the Baltic-Ladoga and Leno-Tunguska basins of the phosphorite ore of the shell type are known.

Phosphorite ore of shell rock type of the Baltic-Ladoga phosphoriferous basin is also known (Vayderma MA Obolovye phosphorites as raw materials for the chemical industry. - Chemical industry, 1963, No. 5, pp. 23-38. Bushinsky GI Petrography of phosphorites of the Western region. - In collection: Agrochemical ores of the USSR, vol. 3, part II, 1934, pp. 154-201 Trushina MI, Nalivkina AI Geological structure and types of ores. - Proceedings of the State Institute of Chemical Economy, 1974, issue 26 , p.32-51) and represents the quartz sands of the Packerortian horizon of the Lower Ordovician with lenses of dolomitic sandstones and p Covina phosphate brachiopods. The main components of shell rock type phosphorite ore of the Baltic-Ladoga phosphoriferous basin are quartz, carbonates, pyrite and calcium phosphate, which is represented by fragments of shells of phosphate brachiopod Obolidae of the Lower Ordovician age (470-490 million years ago), 1-15 mm in size and consisting of hydroxyl fluoropapatite ( biogenic apatite-francolite), and is a useful component in the traditional use of this phosphorite ore as a raw material for the industrial production of phosphoric acid, waste cat cerned is phosphoric flour, currently used as a mineral fertilizer. Phosphorite ore of the shell rock type of the Baltic-Ladoga phosphorite-bearing basin, which has very significant reserves of, according to rough estimates, billions of tons, for example, phosphate ore of the Kingisepp deposit (Leningrad region), contains more than 25 wt.% Biogenic apatite (phosphatized brachiopod shells).

The authors of the present invention by the method of neutron activation analysis, they found an increased gold content in the phosphorite ore of the shell rock type of the Baltic-Ladoga phosphoriferous basin, reaching a maximum value of 20 g / t with an average value of about 0.48 g / t. As the authors of the present invention suggest, the mechanism of gold fortification of phosphate rock of the shell type is natural adsorption of gold chlorides at the stage of diagenesis and / or epigenesis, followed by restoration of gold to a free-metal state on the surface of biogenic apatites. Naturally, concentrates of phosphorite ore of shell rock type, obtained, for example, by its flotation or gravitational enrichment, are characterized by an even higher gold content.

Scanning electron microscopy showed that gold is morphologically represented by particles of 2-35 microns in size, which are located on the surface of the brachiopod shells of biogenic apatites and have a fineness of 850-980 gold. At the same time, lead, copper and silver were found in golds, amounting to 1-2 wt.% In total, and no impurities of arsenic and antimony were detected. The latter creates the prerequisites for a relatively easy recovery of gold from phosphate rock of the shell type, which does not require its preliminary opening.

Example. In laboratory conditions, a weighed portion of a concentrate of phosphorite ore mined in the northwestern section of the Kingisepp deposit, weighing 50 g, was used using 0.1 N HCI, which dissolved in approximately 15 minutes. Dozens of gold grains up to 25 microns in size, having an isometric angular or film-like shape, were found in the residue. These gold grains contained on average 93.2 wt.% Gold, 1.1 wt.% Silver, 0.3 wt.% Copper and 0.3 wt.% Lead. This experiment allowed us to estimate the gold content of about 5.7 g / t.

Under laboratory conditions, gold was extracted from the concentrate obtained at the Phosphorite plant (Kingisepp, Leningrad Region) from phosphate rock of the shell-rock type of the Kingisepp deposit of the Baltic-Ladoga phosphoriferous basin. To do this, 5 kg of concentrate were placed in a container with a volume of 20 dm ³ with 15 dm ^{3 of} distilled water and a chlorine-air mixture was supplied in a ratio of 1: 5 at a temperature of 120 ° C for 72 hours. Then, the ion-exchange resin AM-2B10P was loaded into the obtained hydrochloric acid solution for 15 hours as a sorbent. After annealing the sorbent, the residue was analyzed using the inductively coupled plasma method, which showed a degree of gold extraction from the initial concentrate of 70-75%.

The technology of industrial extraction of gold from phosphate ore concentrate of the Baltic-Ladoga basin can be based, for example, on well-known and well-established processes for its chlorination (Zyryanov MN, Leonov SB Chloride metallurgy of gold. - M.: SP INTERMET ENGINEERING, 1997, p.174-283) or cyanide (Strizhko L.S. Metallurgy of gold and silver: a textbook for universities. - M .: MISIS, 2001, p.163-181. The practice of processing gold ores using cyanide / Zelenov V .I., Baryshnikov I.O., Shtryneva E.M. - M .: Central Scientific Research Institute of Information and Technical and Economic Research of Non-Ferrous Metallurgy, 1968, pp. 13-43, 48-50, 67-71, Lodeishchikov VV Technology for the extraction of gold and silver from refractory ores, Volume 1. - Irkutsk, JSC Irgiredmet ", 1999, p.29-34, Fig.1.2, p.78-342. Lodeishchikov VV Technology for the extraction of gold and silver from refractory ores. Volume 2. - Irkutsk, OJSC" Irgiredmet ", 1999, p.344 -712).

For example, cyanidation of a shell rock type phosphorite ore concentrate of the Baltic-Ladoga basin for gold recovery in the most general case may include the following main technological operations:

- grinding the concentrate to a particle size that provides the necessary completeness of the opening of gold;

- mixing the crushed concentrate with an alkaline cyanide solution, for example, with a solution of sodium cyanide with a concentration of 0.1-0.5 g / l, in agitators of a mechanical, pneumomechanical or pneumatic type;

- separation of gold-containing solutions from the solid part of the pulp by thickening and filtration methods;

- precipitation of gold from solutions by cementation on zinc dust;

- processing of gold-bearing sediments (leaching with acids, firing, smelting) to obtain rough metal gold, then sent to refineries.

Thus, the present invention provides an expansion of the arsenal of minerals for industrial production of gold.

Claims (1)

A method of extracting gold from a concentrate, including cyaniding or supplying a chlorine-air mixture to obtain cyanide or hydrochloric acid gold-containing solutions, respectively, and extracting gold from them by sorption or cementation, characterized in that a shell rock type phosphorite ore concentrate of the Baltic-Ladoga basin is used as the initial concentrate .