RU2196759C2 - Potash fertilizer manufacture process - Google Patents

Abstract

FIELD: fertilizers. SUBSTANCE: flotation-mediated manufacture of potash fertilizers from sylvinite ores consists in that classification of froth product is conducted together with centrifugate, filtrate, and wash-out from band filter drain pans after dehydration of concentrate, fraction below 0.1 mm being subjected to concentration and desludging and fraction above 0.1 mm subjected to repurification. EFFECT: improved quality of product and reduced loss of valuable product. 1 dwg, 2 tbl

Description

 The invention relates to the field of potash fertilizers from sylvinite ores by the flotation method and can be used at the enterprises of OJSC Uralkali, OJSC Silvinit and others to obtain high-quality fertilizers.

 Known methods for producing potash fertilizers, including de-cladding and flotation of crushed ore, classification of the foam product, purification and dehydration of the concentrate (GDR patent 142873, class C 05 D 1/02, 1980, USSR copyright certificate 1351911, class C 05 D 1/02 C 01 D 3/08, 11/15/87).

 The disadvantages of these methods are low selectivity, a complex technological scheme, low content of potassium chloride in the concentrate.

 The purpose of the invention is to improve the quality of the concentrate, reducing the loss of useful component.

 A method for producing potash fertilizers includes de-cladding and flotation of crushed sylvinite ore, classification of the foam product together with a centrate, filtrate and washing from the filter pan pallets after dehydration of the concentrate, a fraction of more than 0.1 mm is sent for cleaning, and a fraction of less than 0.1 mm for thickening and deslaming.

 Table 1 presents the characteristics of the foam product, centrate, filtrate and flush from the pallets of belt vacuum filters in fractions.

 As can be seen from table 1, the fraction of particles less than 0.1 mm in these products contains a relatively small amount of potassium chloride 45-48% and a significant amount of insoluble residues 3.2-3.5%, which negatively affects the work of cleaning - increased losses of potassium chloride and deteriorating quality indicators of the concentrate. Therefore, it is more expedient to isolate a fraction of particles of less than 0.1 mm and direct it to thickening together with intermediate products and process it in a closed cycle on the main flotation according to known technology.

 The composition of the products of classification according to the 0.1 mm fraction is presented in Table 2. The classification food is a pre-mixed foam product with a centrate, filtrate and flushing from the pallets of belt vacuum filters.

 As can be seen from table 2, as a result of classification according to the 01 mm fraction, a product (fraction +0.1 mm) with improved characteristics for the content of potassium chloride and insoluble residue is fed to the purification, which will positively affect the work of the purification - the loss of potassium chloride with intermediate products will decrease and increase the quality of the concentrate.

 The drawing shows a diagram of an implementation of a method for producing potash fertilizers.

 After grinding, the ore is decontaminated and floated. The resulting foam product is mixed with a centrate, filtrate and flushing from the pallets of belt vacuum filters and sent for classification by 0.1 mm fraction. The fraction +0.1 mm goes to the purification, and the fraction - 0.1 mm together with the intermediate products is concentrated and enriched in a closed cycle on the main flotation. The concentrate obtained by cleaning is dehydrated on centrifuges and belt vacuum filters and enters the drying section, and the centrate, filtrate and washing out of the belt vacuum filter pallets, as was shown above, are mixed with the foam product.

 Example. A foam product with a content of 76.4% potassium chloride and 1.6% insoluble residue with a density of W: T = 1.1 is mixed with a centrate, filtrate and rinsing from the trays of belt vacuum filters. The resulting product with a content of 78.4% potassium chloride and 1.5% insoluble residue with a density of W: T = 1.3 is sent for classification. In the classification process, a fraction of more than 0.1 mm with a content of 88.5% potassium chloride and 0.8% of an insoluble residue with a density of W: T = 0.7 and a fraction of less than 0.1 mm with a content of 46.3% of potassium chloride and 3.3% insoluble residue with a density of W: T = 3.9.

 A fraction of more than 0.1 mm is diluted with mother liquor to a density of Zh: T = 3.5-4.0 and sent for purification, and a fraction of less than 0.1 mm is thickened together with intermediate products and with a density of Zh: T = 2.5-3 , 0 are sent to deslaming.

 This method allows to obtain a high quality concentrate with less loss of useful component.

Claims (1)

 A method for producing potash fertilizers, including de-cladding and flotation of crushed ore, classification of the foam product, purification and dehydration of the concentrate, characterized in that the classification of the foam product is carried out together with the centrate, filtrate and washing from the filter belt pallets after dewatering the concentrate and a fraction of more than 0.1 mm sent for cleaning, and a fraction of less than 0.1 mm for thickening and desliming.

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