CA2739660A1

CA2739660A1 - Method for producing a bulk concentrate

Info

Publication number: CA2739660A1
Application number: CA 2739660
Authority: CA
Inventors: Andrei Filippovich Smetannikov; Dmitriy Valentinovich Onosov; Aleksey Alekseevich Chistyakov; Pavel Yurievich Novikov; Viktor Andreevich Sinegribov; Arkadiy Evgenievich Krasnoshtein (Deceased)
Original assignee: ZAKRYTOE AKCIONEERNOE OBSHESTVO 'URALKALIY-TECHNOLOGIYA'
Current assignee: ZAKRYTOE AKCIONEERNOE OBSHESTVO 'URALKALIY-TECHNOLOGIYA'
Priority date: 2008-09-29
Filing date: 2009-09-08
Publication date: 2010-04-01
Also published as: WO2010036143A1; EP2281636A4; RU2385772C1; IL211922A0; BRPI0919425A2; EP2281636A1; CN102202794A

Abstract

The invention relates to methods for producing a bulk enrichment concentrate for extracting noble metals from clay-salt waste (slurries) from plants which process potassium-magnesium ores and rock salt. The method for producing a bulk concentrate for extracting noble metals involves the three-stage hydrocyclone separation of the slurries and the isolation of the concentrate. The bulk concentrate produced by the hydrocyclone separation in the form of a mixture of sedimentary and floating material with a 1:1 solid-to-liquid ratio is desiccated, pre-dried, granulated and then dried.

Description

METHOD FOR PRODUCING A BULK CONCENTRATE
CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a U.S. national phase application of a PCT
application PCT/RU2009/000456 filed on 8 September 2009, published as W02010/036143, whose disclosure is incorporated herein in its entirety by reference, which PCT
application claims priority of a Russian Federation patent application RU2008/138814 filed on 29 September 2008.

FIELD OF THE INVENTION

[0002] The invention relates to methods of producing the concentrate being enriched for precious metals recovery from clay-salt residues (slimes) of plants processing potassium-magnesium ores and rock-salt by the methods of pyro- and hydro-metallurgical processing.
BACKGROUND OF THE INVENTION

[0003] From the technical viewpoint there are known methods of material dewatering (dehydration) which are close to the invention (Reference book on ores enrichment. Special and auxiliary processes, Moscow, publisher "Nedra", 1983, pp.77, 78, 96-98, 100, 102, 108, 109. A.A. Abramov, S.B. Leonov. Non-ferrous metal ores enrichment, Moscow, publisher "Nedra", 1991, pp.35, 37). These methods include dewatering of materials of various lump sizes in classifiers, filtering centrifuges, vacuum filters, press-filters, drying ovens, etc. The aforesaid methods are intended for maximal separation of liquid phase from solid phase for materials of a certain lump size. However, each of these methods taken separately is not intended for separating the liquid phase of "slimes" due to the complexity and peculiarities of substantial and granulo-metric composition of the material. It is known that more than 70%
of the material has a lump size less than 0.1 mm and more than 20% of the material has a lump size less than 0.044 mm. Thusly, during the use of filtering centrifuges providing residual humidity less than 5% at the material lump size more than 1 mm, in our case, some portion of the material will transfer into the filtrate together with a portion of useful component.

[0004] For the same reason, press-filters cannot be used. The use of drying ovens is impossible without a preliminary dewatering. Therefore, for dewatering of slimes after the centrifuging, a set of methods is necessary for dewatering carried out by several apparatuses.

[0005] There is known a method of concentrate production from clay-salt residues of enterprises, processing potassium-magnesium ores and rock-salt, for recovery of precious metals (Russian Federation Patent # RU2256504 published on July 20 2005). This method includes at least a two-stage hydrocyclone treatment of slimes with the extraction of concentrate. Hydrocyclone treatment is carried out in two or three stages and the concentrate of hydrocyclones is a solid phase of insoluble residue of the slimes.

[0006] Initially, the slimes with a solid-to-liquid (S:L) ratio of 1:3 are delivered for the hydrocyclone treatment. At a first stage of the hydrocyclone treatment the following operations are carried out: - extraction of concentrate in the form of insoluble residue coarse fraction, - discharge of the hydrocyclone treatment first stage product in the form of insoluble residue fine fraction and salt solution. Then the first stage product is processed into pulp with a (S:L) ratio of 1:8, and is forwarded for re-cleaning on a second stage of the hydrocyclone treatment with an extraction of the concentrate in the form of residual fraction of the slime insoluble residue and a discharge of the hydrocyclone treatment second stage product in the form of salt solution with the subsequent joining of the concentrates extracted by the hydrocyclone treatment. In case of a high residual content of insoluble residue in the hydrocyclone treatment second stage product, an additional third stage of the hydrocyclone treatment is carried out, therefore the slimes of mineral-salt production plants and flotation plants are processed.

[0007] A disadvantage of this method is a high enough content of moisture and impossibility to carry out the further pyro- and hydro-metallurgical processing.

[0008] A method of concentrate production from clay-salt residues of plants processing potassium-magnesium ores and rock-salt according to patent RU 2284221 (published on September 27, 2006) is also known. This method includes hydrocyclone treatment carried out in three stages; collective concentrate of the hydrocyclons treatment (pulp) is a solid phase consisting of sedimentary and floating part, represented by residue of slimes insoluble in water and the liquid phase.

[0009] The pulp has the (S:L) ratio = 1:1 (solid and liquid phases) and the residual content of salts of K and Na is no more than 15%.

[0010] A disadvantage of this method is a high enough content of moisture and impossibility to carry out the further pyro- and hydro-metallurgical processing.

[0011] The proposed invention resolves the issue of pulp transformation after hydrocyclone treatment into an enriched concentrate in the form of dry granules with a diameter from 8 to 15 mm, suitable for pyro- and hydro-metallurgical processing, which retains all the properties of primary slimes, i.e. all the content sum of precious metals and a content of 20+5% of salts in the solid state.

[0012] To achieve the aforesaid technological result in the inventive method of collective concentrate production for recovery of precious metals including a three-stage hydrocyclone treatment of slimes with the extraction of collective concentrate, the collective concentrate, being a mixture of sedimentary and floating materials with a (S:L) ratio of 1:1, is dewatered, pre-dried, granulated, and it has the following distinctive features: the concentrate is demineralized (salts removal) until the salt content is 20 5%, granulated till the granules reach a size of 8 or 15 mm, dried till the humidity is 0.5%.

[0013] The distinctive features which make the proposed method different from the method, described as "the closest", are the following: collective concentrate produced after the hydrocyclone treatment, being the mixture of sedimentary and floating material with the (S:L) ratio = 1:1, is dewatered, pre-dried, granulated, then dried.

[0014] Due to these features, the inventive method allows for obtaining not just pulp with the (S:L) ratio = 1:1, but a collective concentrate, i.e. granulate containing (remaining) a base amount of sedimentary and floating materials, as well as natural and technogenic organic substances having significant fractions of precious metals.

[00151 The proposed method contemplates the deployment of equipment for gradual separation of moisture to a threshold allowing for granulation with the attaining of granules having a diameter from 8 to 15 mm with the following after-drying up to a moisture of 5%
with keeping all qualities of the initial slime, including natural and technogenic organic substances.

[00161 The results by this method are: a maximal saving of the non-soluble residue of slimes, natural and technogenic organic substances, and obtaining concentrate in the form of granules with a humidity of 5%, a granule diameter of from 8 to 15 mm, and a remaining content of salt of 20+5%. The insoluble residue is a concentrate containing compounds of Au, Pt, and Pd, having a mineral base (in a descending order): anhydride, dolomite, quartz, feldspar, chlorite, hydro-mica, hydroxides of Fe, sulphides, and organic materials represented by natural and technogenic substances.

[0017] For obtaining the concentrate it is necessary:

1. To provide removal of excessive moisture by means of centrifuging after drying in auger furnace and subsequent granulation.

2. In the process of granulation and drying in drum-type furnace to obtain a concentrate with the salt content of 20+5% and granule size of from 8 to 15 mm for subsequent pyro-metallurgical processing.

[00181 The method is carried out in the following way. After hydrocyclone treatment, pulp (pre-concentrate) is forwarded to a centrifuge where the whole of insoluble residue while the whole set of components transfers into agglomerated cake, and the salt solution transfers into centrifuge effluent. Then the cake is forwarded to an auger furnace where the material is finally dried to a humidity of 15%.

[00191 Then the material with the humidity of 15% is forwarded to a die-type granulator for granulation, from which it is discharged in the form of granules with the diameter of from 8 to 15 mm, after which it is forwarded to a drum-type furnace for final drying to a humidity of 0.5%.

[0020] The need of creating such production sequence is stipulated by the fact that the pyro- and hydro-metallurgical processing is possible in the form of granules with the diameter of from 8 to 15 mm and the salt content of 20 5%.

[0021] The collective concentrate from clay-salt wastes of industrial plants processing potassium-magnesium ores and rock-salt, used in the process, is the slimes of mineral-salt production plants and flotation plants with a pulp density of 1.3 g/cm3 and a (S:L) ratio = 1:3.
[0022] A distinctive feature of the concentrate is the following: a high content of organic substance represented by natural and technogenic substances (amines and polyacrylamide).
It's worth to note that for the mineral-salt production plants the organic substance content (total) doesn't exceed 1.5%, while in our example the total content of organic substances has reached 3%, which is associated with including of an amination, at the stage of vacuum crystallization in the mineral-salt production process. This provides the entering of amines into the slimes and facilitates blocking and aggregation of the precious metals organic compounds.

[0023] The second distinctive feature is the need of concentrate production in the form of granules with the diameter is from 8 to 15 mm and the residual salts content is 20 5%.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED IS DEFINED AS FOLLOWS:

1. A method of collective concentrate production for precious metals recovery, including a three-stage hydrocyclone treatment of slimes with the extraction of concentrate differing in that the collective concentrate, obtained after hydro-cyclone treatment and represented by a mixture of residue and floating materials with a (S:L) ratio = 1:1, is dewatered, pre-dried , granulated and dried up.