RU2354457C1 - Method of concentrating potassium containing ore - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention refers to process of flotation concentration of minerals and can be implemented for concentrating ores, mainly potassium ore. The method of concentrating potassium containing ore consists in crushing, close-size grading, crumbling up, de-sliming and successive flotation of sylvite. Suspended ore with contents of non soluble residue up to 10%, where fine dispersed amorphous particles present up to 40 % of non soluble residue, is preliminary graded by size 0.7 mm producing through and oversize product, the latter is re-ground. The re-ground product is graded successively in two stages by size 1 and 0.7 mm, also oversize product of the 1-st stage of close size grading of +1 mm size is returned to re-grinding, while through product of -1 mm is directed to the 2-nd stage by size 0.7 mm, thus through product is obtained, which is combined with through product of preliminary close-size grading of ore suspension. Combined ore flow of up to 0.7 mm size is de-slimed by the method of slime flotation producing foamy waste slime and chamber product, out of which sylvite is floated. Oversize product of the 2-nd stage of close-size grading of 1+0.7mm size is de-slimed, and further sylvite is floated.

EFFECT: increase efficiency of concentration.

1 dwg

Description

The invention relates to the technology of flotation concentration of minerals and can be used to enrich ores, mainly potash.

Known flotation method of beneficiation of potassium ores with a high content of insoluble residue (n.o.), including crushing, classification, grinding of feedstock, conditioning ore pulp with a flocculant and collector, single-stream desulphurization of the pulp by the slurry flotation column method and subsequent flotation of sylvin (P. 2132239, MKI ⁶ B03D 1/02, publ. 06/27/99, BI No. 18, 1999).

The disadvantage of this method is the low selectivity of the process of dehumidification when the content of N.O. in ore more than 6% and, as a result, an increase in the loss of a useful component with sludge.

Closest to the proposed invention is a method of beneficiating potassium ores, including crushing, classification, grinding, deslaminating and subsequent flotation of potassium chloride, while before deslaming the suspended ore is sent for preliminary classification to obtain two streams, which are deslaminated separately, and the under-sizing product of preliminary classification after treatment with reagents, they are sent to sludge flotation to produce foam dump sludge and chamber of product, the screen overflow of the provisional classification is milled and produce its reclassification, whereupon undersize product re-classification is combined with the product chamber desliming, and the combined stream directed to the ore slurry to control desliming subsequent flotation of sylvite. (Patent RU No. 2245742, IPC B03D 1/02, publ. 10.02. 2005, BI No. 4).

The disadvantage of this method is the use of separate two-stream de-slamming only in the process head with subsequent single-stream de-slamming, which reduces the efficiency and selectivity of de-slamming, and also leads to the need for secondary classification of the main sylvin flotation nutrition and complication of the sylvin flotation process.

The technical result of the invention is the expansion of the ore base for the enrichment of potassium-containing ores, by increasing the efficiency of de-sludge ore with a grade of N.O. up to 10%, reducing the loss of the useful component with sludge flotation sludge and tailings while reducing reagent consumption and expanding the range of products obtained.

To achieve the specified technical result in a method for beneficiating potassium ores, including crushing, classification, grinding, suspended ore with a content of up to 10% insoluble residue, with up to 40% n.a. it is represented by finely divided amorphous particles, pre-classified by fineness of 0.7 mm to obtain sublattice and oversize products, the latter are finely ground and classified sequentially in two stages by fineness of 1 mm and 0.7 mm, while the oversize product of the 1st stage of classification of fineness +1 mm is returned to regrinding, and an under-sieve product of -1 mm is sent to the 2nd stage of classification by size of 0.7 mm to obtain an under-sieve product, which is combined with an under-sieve product of preliminary classification ore ore suspension, and then the combined (1st) ore stream with a grain size of up to 0.7 mm is de-slurry by the method of slurry flotation to obtain a foam dump sludge and a chamber product from which sylvin is floated, while the sieve product of the 2nd stage of classification with a particle size of 1+ 0.7 mm (2nd ore stream) is de-slurred, and then sylvin is floated.

The openness of the minerals and the dispersion of the particles of n.o., characterizing their flotation activity, were identified as a result of studies of the material composition of n.a. (1,2).

Improving the selectivity of the disclosure of minerals in the processes of crushing, grinding, followed by classification and sludge flotation allows, in turn, to increase the extraction of a valuable component and reduce its loss with tailings in the form of overgrown grains of minerals and splices “silvin-halite”.

Insoluble residue in potassium ore is represented by up to 40% finely dispersed amorphous particles and flotative silicate minerals, regardless of the mass fraction of the total grade of no. in the ore. The classification of suspended ore by fineness of 0.7 mm contributes to a more efficient separation of free n.o. into the sublattice product, which is removed in the subsequent stage of decontamination. Experimentally at the ore BKPRU-2 with grade n.o. 10.2% found that the extraction of N.O. in the process of slurry flotation from ore of the 1st ore stream (ore size up to 0.7 mm) reaches 80-85% when the KCl content in the foam slurry product is not more than 15% and the process takes 4 minutes. Thus, in the process of sludge flotation of the 1st ore stream, 80-85% of finely dispersed n.o. particles are removed, which greatly simplifies the subsequent flotation processes.

Extraction n.o. of polydisperse ore during sludge flotation is not more than 70%, while the speed and selectivity of the process are reduced, the overgrinding of more fragile sylvin particles is growing.

In addition, the increased content of large salt particles in the pulp in the process of sludge flotation leads to greater destruction of floccula n.o. and increased flocculant consumption. Clay-carbonate sludge is characterized by high sorption activity and sorb amines in saline solutions, which leads to a significant decrease in the floatability of precisely large fractions of sylvin, and, in turn, affects the enrichment indices and contributes to an increase in the loss of useful component with tails. With an increase in the size of floated particles, reagent costs increase.

The regrinding of the oversize pre-classification product helps to reveal the growth of salt minerals, while changing their aggregate state and increasing the yield of a fine-grained ore stream (fineness up to 0.7 mm). Separation of ore into two autonomous (independent) streams that go through all stages of enrichment independently of each other allows us to take into account the difference in physical and physicochemical properties of useful minerals and sludge particles and, as a result, significantly increase the efficiency of sylvin extraction and reduce the loss of useful component with tails.

A distinctive feature of the proposed scheme for the enrichment of potassium-containing ores is that in the process of preparing flotation feed, each extracted ore stream passes de-slamming and eliminates the need to classify the feed of the main sylvinite flotation.

The method is illustrated in the diagram (drawing) and is as follows.

Dry-crushed ore with a grain size of up to 20 mm is suspended in a circulating saturated solution of potash production in a weight ratio of w: t = 1.5-2.0 and preliminary classified according to its size class 0.7 mm on arc screens with a slot width of 1.4-1, 5 mm to obtain two products: under-sieve and over-sieve.

Oversize product is crushed in a core mill at w: t = 0.8-0.9 and classified at the first stage by particle size 1.0 mm at a power density w: t = 1.5. Oversize product of classification with a grain size of -1 mm at w: t = 0.8-0.9 is returned to grinding in the mill, and the under-sieve product with a grain size of -1 mm at a density of w: t = 1.5 is classified at the second stage according to a particle size of 0.7 mm at product density w: t = 2.5-3.0. The sublattice product of the second classification stage with a particle size of -0.7 mm is combined with the sublattice product of the preliminary classification of ore suspension (1st ore stream) and treated with reagents: flocculant, for example Accofloc 110, in an amount of 450 g / tn.o. in ore, collector, etomine NT / 40 by AKZO-Nobel, in an amount of 200 g / t n.o. in ore - and fed to the sludge flotation, preferably on pneumatic flotation machines, after which receive foam dump sludge and chamber product. Up to 80-85% n.o. is recovered from the foam waste slurry. when the content in the solid phase is not more than 15% KCl. After thickening in the thickener, the dump sludge is dumped into the sludge dump. The chamber product is treated with reagents and floated with fine-grained KCl, which, after centrifugal dehydration and drying, is the finished product.

Oversize product of the second stage of re-classification with a particle size of -1.0 + 0.7 mm is sent to de-slurry, which, depending on the content of n.o. in ore is carried out by known methods: hydromechanical in hydrocyclones, hydroseparators (n.o. in ore 2-5%), by depression n.o. reagent depressant, for example, urea-formaldehyde resins (n.o. in the process feed 1-3%), or a combination of methods, including sludge flotation.

Using the method will expand the ore base for enrichment, process potassium-containing ores with a total grade of n.o. up to 10%, including with the content of finely dispersed amorphous particles in n.o. up to 40%, to increase the extraction of the useful component from ore by reducing losses with sludge flotation sludge and tailings while expanding the range of finished products.

Claims (1)

A method for beneficiating potassium ores, including crushing, classification, grinding, deslamination and subsequent flotation of sylvin, characterized in that the suspended ore containing up to 10% insoluble residue (n.o.), with up to 40% n.o. it is represented by finely divided amorphous particles, pre-classified by fineness of 0.7 mm to obtain sublattice and oversize products, the latter are finely ground and classified sequentially in two stages by fineness of 1 mm and 0.7 mm, while the oversize product of the 1st stage of classification of fineness +1 mm is returned to regrinding, and an under-sieve product of -1 mm is sent to the 2nd stage of particle size classification of 0.7 mm to obtain an under-sieve product, which is combined with the under-sieve product of preliminary classification p suspension slurry, and then the combined (1st) ore stream with a grain size of up to 0.7 mm is de-slurry by the method of slurry flotation to obtain a foam dump slurry and a chamber product from which sylvin is floated, while the sieve product of the 2nd stage of classification with a particle size of 1 + 0 , 7 mm (2nd ore stream) are de-slammed, and then sylvin is floated.