RU2083630C1 - Method for dust suppressing of finely ground potassium chloride - Google Patents

Abstract

FIELD: production of finely ground dispersed potassium chloride which does not produce dust, said potassium chloride being prepared by flotation enrichment. SUBSTANCE: method involves treatment of finely ground potassium chloride by mixture of polyethylene glycol with formal of dioxane alcohol, its quantity being 10-40 mass %. Said formal may be side product of production of dimethyl dioxane. EFFECT: improved efficiency of the method. 2 cl, 1 tbl

Description

 The invention relates to the use of polyethylene glycols for the production of non-dusting, fine-grained potassium chloride obtained by flotation enrichment.

 For dust suppression of potassium chloride, it is known to use polyethylene glycols with a molecular weight of 120-400 [2] however, when using this dust suppressor, the rheological properties of the conditioned product (fluidity, caving angle) deteriorate, the consumption of polyethylene glycol is quite high (3.0-4.0 kg / t). Using a combination of polyethylene glycol with urea [1] can reduce the consumption of polyethylene glycol (up to 2.0 kg / t), but there is a significant deterioration in the rheological properties of the finished product.

 The invention improves the dust suppression effect of polyethylene glycol: reduce its consumption without deterioration of the rheological properties of the finished potassium chloride. This is achieved by the fact that in the method of dust suppression of fine-grained potassium chloride by processing polyethylene glycol with an organic additive, 10-40 wt. formaldehyde dioxane alcohol.

 When conditioning the fine-grained potassium chloride obtained by flotation enrichment, a certain amount (70-120 g / t) of the collector of salts of aliphatic amines is present on its surface, which causes hydrophobization of the surface of the material. When eliminating the dustiness of such a product, the combination of hydrophilic (glycol) and hydrophobic (formal) properties of the conditioning reagent is of great importance. The addition of dioxane alcohol formulas allows to reduce the dust suppressor consumption and not to deteriorate the rheological properties of the conditioned potassium chloride obtained by flotation enrichment. Formals of dioxane alcohols are soluble in polyethylene glycol, and at the indicated ratio the mixture is soluble in water.

 As formulas of dioxane alcohols, a by-product of the production of dimethyldioxane can be used as the target product in the production of synthetic rubber.

 The proposed method was tested in laboratory conditions on a fine-grained flotation concentrate of JSC Uralkali containing 14.2% of a class less than 0.1 mm and aliphatic amine hydrochloride (collector) 85 g / t. After treatment with a dust suppressor, the dustiness of the product was determined (according to TU 113-13-40-87 p. 4.3.9), the angle of caving and the yield coefficient by standard methods (EI Andrianov, "Methods for determining the structural and mechanical characteristics of powder materials" M. Chemistry, 1982).

 As dust suppressors used: "Dust suppressor" according to TU 38.602-09-18-90, containing a mixture of mono-di-tri-tetra and pentaethylene glycols (PEG); a mixture of these polyethylene glycols with dioxane alcohol formaldehyde; a mixture of these polyethylene glycols with a by-product of dimethyldioxane production.

 The test results are shown in the table. As follows from the data in the table, with the proposed ratio of polyethylene glycol and formaldehyde of dioxane alcohols (experiments 4-6) with a low dust suppressor consumption, the required dust level is achieved (for 1 kg of this product the dust norm is not more than 250 mg of dust) at a sufficiently low caving angle and coefficient fluidity of the conditioned product. Similar results are achieved when using formaldehyde dioxane alcohol by-product of the production of dimethyldioxane (experiment 10).

 To achieve the required dust level when using polyethylene glycol, an increased consumption of dust suppressor is required, while the rheological properties of the material are significantly impaired (experiments 2 and 3).

 Due to the best hydrophilic (glycol) and hydrophobic (formal) balance, the proposed reagent mode makes it possible to achieve the required dust level during processing of flotation fine-grained potassium chloride with a reduced dust suppressor consumption and to obtain a finished product with the necessary rheological properties, which leads to an improvement in its overload conditions. A change in the ratio of glycol and formal outside these intervals leads to both deterioration of the dust suppressor and the rheology of the finished product (experiments 7, 8). Similar results were obtained using the formaldehyde of dioxane alcohols without polyethylene glycol (experiment 9), which indicates that the hydrophilic properties of the dust suppressor (the presence of glycol) also play a significant role in the processing of fine-grained, hydrophobized material.

 The conditioning of the material according to the proposed method can be carried out in any units that provide effective mixing, for example, in spiral mixers with a residence time of 40-60 s. The dust suppressor is supplied to the mixer by a jet, or sprayed by a nozzle. The recommended temperature of the processed potassium chloride is 70-80C.

 Example. Fine-grained potassium chloride obtained by flotation enrichment after drying (class content less than 0.1 mm 14.2 wt.% Moisture content 0.1 wt. And dust content 1920 mg / kg, treated in a mixer with polyethylene glycol with the addition of 25 wt. Formula of dioxane alcohols at a flow rate of 2 , 0 kg / t of potassium chloride. At the same time, an anti-caking agent is added: an aqueous solution of ferrous potassium chloride at a flow rate of 50 g / t. The resulting dust-free potassium chloride with dust content of 148 mg / kg is sent to the finished product warehouse. Oristà potassium is achieved by reducing the flow rate of polyethylene glycol and allowing the release of additional product with improved physical and mechanical properties.

 The proposed method of dust suppression of potassium chloride is used in the production of potassium chloride at JSC Uralkali.

Claims (2)

 1. The method of dust suppression of fine-grained potassium chloride by treating it with a polyethylene glycol reagent, characterized in that the polyethylene glycol is used in a mixture with 10 to 40 wt. formaldehyde dioxane alcohol.  2. The method according to claim 1, characterized in that the formaldehyde of dioxane alcohol is used as a by-product of the production of dimethyldioxane.

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