SU966089A1 - Composition for producing granulated potassium and magnesium fertilizer - Google Patents

Description

FIELD: technology. Tin production of potash fertilizers and, in particular, potash-magnesium and can be used in the processing of high clay sylvinite ores, containing up to 6-12% of the insoluble residue and 1-2% of the chloride magnets.

During the processing of these ores into potash fertilizers, a significant amount of clay-salt effluent is formed.

In addition, in the processing of sylvinite ores, excess chlorine magnesium liquors (sod. MDS 2 -29%) y- are formed. production waste. Issued to. potash plants fine-grained chloride, potassium contains up to 15-20% of dust fractions of class minus 0.1 mi, which leads to dustiness during loading and unloading. works, contributes to the caking of the product during storage and trans porting.

The use of waste, potash production in the form of clay-salt sludge, dust-like fractions of potassium chloride and magnesium chloride solution to obtain fertilizers would provide an additional amount of granular fertilizer | 1,

reduce the volume of sludge storage, thereby reducing environmental pollution.

A known composition for the production of granulated potassium-magnesium fertilizer (K-iO 40%, MgO 5%), including flotation potassium chloride (K2.0 58% if, hl-salt-salt slurry and kieserite solution. salt solids with a solids content of 30–33%, containing 1– (Iy up to 10% is mixed with the flotation concentrate after it is filtered in a drum vacuum filter. The dehydrated product is diluted with a solution of kieserite in a mixer, which also returns the retur of small granules of the finished product (class minus 15 mm).

 A mixture of products from the mixer in

20 as wet granules (moisture 12%) enters the dryer drum, where they are consolidated and dried 1. However, in the known method clay-salt needles (solids content 30-33%) are used without prior it. dehydration, this requires additional energy consumption of water and thereby increases the cost of the finished product.

30 ta. In addition, the ifKaaaHHbJfl method cannot be applied to domestic potash plants, since components such as kieserite are not contained in the sylvinite series processed. The aim of the invention is to improve the strength of the granules, reduce the quality of the test and improve the agrotechnical properties. The goal is achieved by the fact that the composition for obtaining granulated potassium-magnesium fertilizer potassium chloride, including an aqueous solution of magnesium salt and clay-salt slurry, additionally contains sodium carbonate or sodium silicate, and as the magnesium salt - magnesium chloride in the following ratio of components, wt.% : Potassium chloride 45-55 Magnesium chloride 8-12 Clay-salt slurry 10-18 Silicate or sodium carbonate 4-10. Water Remaining In order to protect the environment, production waste is used as a raw material: cyclone dust, obtained when drying and dedusting potassium chloride, excess chlorine liquor and dried to a solid 55-70% clay-salt slurry. To increase the productivity of the dryer-granulator, clay-mud sludge is pre-dewatered, for example, in a precipitation centrifuge to a concentration of the solid phase in the suspension to 55-70%. .. The use of potash production wastes in the indicated ratio allows obtaining durable and non-caking granulated potassium-magnesium fertilizers with an optimal content of magnesium (MgO 5%) and potassium (40%). The original clay-salt slurry with a solids content in suspension of 30-33% is fed, for example, to a precipitation centrifuge. The dehydrated clay-salt slurry 55-70 with the solids content in the slurry enters the mixing tank, where the powdered fraction of potassium chloride and the magnesium chloride solution are fed with a predetermined ratio. A mixed slurry of clay and salt sludge, dust fractions of potassium chloride and a solution of magnesium chloride are sprayed from the mixing tank into a granulator torus dryer. A solution of sodium carbonate or silicate is fed by a nozzle into a pellet dryer on the fertilizer granules formed. A portion of the sodium carbonate or silicate solution can be supplied to the mixer. A drying agent for the granulator dryer is the flue gases obtained by burning fuel oil or gas and supplying cold air. The granulated product from the pellet torus soloilki is fed to the screen, where it is divided into classes +4 mm, -1 mm, +1 M14 and -1 mm. The product larger than 4 mm is additionally crushed in a crusher, classified at the screen, a class of -1 mm is returned to the pellet as a retur to the pellet dryer. The class minus 1 mm, obtained by screening, is returned there as a retour. The finished granulated potassium-magnesium concentrate {-4 mm +1 mm) goes to storage. The waste from the steam-gas dryer granulator is supplied to the dry and wet cleaning system. The dust from the dry cleaning is returned to the granulator torus dryer, or to the mixer, the waste gases from the wet cleaning system are discharged into the atmosphere. According to the proposed method, tests were performed on a unit with a drum granulator-dryer with a diameter of 0.3 m and a length of 1.2 m. A raw mixture containing 60% Kshi chloride, 12% magnesium chloride, 16% clay-salt slurry and 12% water was prepared. . A different amount of sodium silicate or sodium carbonate solution is added to this mixture. After pe- stirring the mixture n: t with simultaneous granulation. The obtained granules are determined by hygroscopicity, (the moisture of the granules after storage for 36 hours at 50 ° C and a humidity of 51%) and the static strength gr. zero . the table shows the dependence of the hygroscopicity and strength of the granules on the amount of additives added.

 As can be seen from the above data, the addition of sodium carbonate or sodium silicate in an amount of 4-10 wt.% Does not contribute to a decrease in hygroscopicity and an increase in the strength of the granules due to the binding of magnesium ions.

With a decrease in the content of additives of about 2% (op. 2 and 7), the hygroscopicity increases (the amount of free magnesium ions increases and, accordingly, the grain strength decreases; zero).

An increase in the content of additives above 10 wt.% Slightly affects the further change in hygroscopic. nosti and durability of granules.

Formulation preparation example. For the production of granulated potassium magnesium fertilizer.

1.4 wt.% Clay-salt sludge (humidity 40%), 46 wt.% Cyclone paper (content KC190%) 24% solution of magnesium chloride (content MgCl, 16% solution of sodium silicate (content Na. KO%) are mixed, with. this get a mixture of the following composition, wt.%:

Potassium chloride 45 Magnesium chloride 8. . Clay salt sludge 10

Sodium silicate 6: water31

The mixture of the indicated composition is subjected to drying and granulation.

Thus, the proposed composition, in contrast to the known, allows 35 s. high technical and economic indicators to master the production of granulated potassium-magnesium fertilizers, from potash production wastes, reduce the volume of sludge flooring facilities and obtain a non-hygroscopic product with enhanced granule strength and improved agrotechnical properties that can be effectively used in agricultural farming 45 for meadow meadows. Ava, corn and other crops. .

Claims (1)

Invention Formula A composition for producing granulated potassium magnesium. fertilizer, including chloride, aqueous solution, magnesium salts and clay and so on. Left sludge, r.t.l.and, and with the fact that, in order to increase the strength of the granules, reduce caking and improve agrotechnical properties, it additionally contains sodium carbonate or silicate, and as a magnesium salt - magnesium chloride in the following ratio of components, wt.%: Potassium chloride 45-55 MapHy chloride. 8-12 Clay salt slurry 10-18 7966089 8 Silicate or carbonate1, Noah Hof Firgla Kali und Salz. sodium 4-10 Review information Quality and water The rest of the assortment of potash fertilizers abroad, Sources of information, pulp, 1, M. / NIITEKHIM taken into consideration during the 1977 examination.