RU1775387C - Method of producing phosphates as fodder additives and as fertilizers - Google Patents

Abstract

The invention relates to a method for producing feed and fertilizer phosphates, which can be used in agriculture as feed additives for animals and as fertilizers for all types of soils. The purpose of the invention is to increase productivity and yield of product fraction of a product. For this, the phosphate feedstock is mixed with aluminosilicate minerals, the resulting mixture is moistened, fired at a temperature of 1350-1500 ° C with the addition of excess air. Calcination is carried out in the presence of a mixture of ferrous and ferric iron compounds, which is added in an amount of 0.5-6.5 wt.% With a mass ratio of Fe / Fe ^ * ^ = - 0.05-10, The performance of the process according to the proposed method 6.0-8.0 t / h. The output of the commercial fraction is 70-78%. 3 3. p. Fs, 4 tab.

Description

The invention relates to a method for producing feed and fertilizer phosphates, which can be used in agriculture as feed additives for animals and as fertilizers for all types of soils.

A known method for producing feed and fertilizer phosphates, comprising mixing phosphate feed with nepheline, firing the mixture at a temperature of 1350-1500 ° C with air supply. In this method, the phosphate feed is mixed with nepheline at a ratio of phosphate feed: nepheline equal to 4.8-5.1: 1, calcium acid phosphates (retur) are added to the charge. then the mixture is moistened to contain 8-9% moisture and granulated with the addition of phosphoric acid. The obtained granules are fired at a temperature of 1350-1500 ° C with air supply, while air is supplied cyclically with a pulsating feed, first with an excess coefficient of 0.8-0.95, and then with an excess coefficient of 1.05-1.20. The cycles are repeated after 1-35 minutes.

A disadvantage of the method is the preparation of a product in which PaOs uev. does not exceed 65-70%. The method is technologically complicated.

The closest to the proposed technical essence and the achieved result is a method for producing feed and fertilizer phosphates, including mixing phosphate raw materials with aluminosilicate minerals, moistening the mixture, roasting it at 1350-1500 C with the supply of excess air. According to this method, nepheline is used as an aluminosilicate mineral, which is added in an amount providing a ratio of PzOs: nepheline 3.4-4; 1. The disadvantage of this method is the low productivity of the process (5.5-6.0 t / h) and a low yield of commercial fraction (1-4 mm) of 40-50%. The purpose of the invention is to increase productivity and yield of product fraction of a product. The goal is achieved in a method for producing feed and fertilizer phosphates, including mixing phosphate raw materials with aluminosilicate minerals, moistening the resulting mixture, firing it at a temperature of 1350-1500 ° C while supplying excess air by firing in the presence of a mixture of ferric and ferric iron compounds which is added in an amount of 0.5-6.5 wt.% with a Fe: ratio of 0.05-10: 1. It is possible to use nepheline, aegirine, albite, analcime, arfvedsonite, astrophyllite as aluminosilicates. biotite, vermiculite, glauconite, mookovit, orthoclase, microcline, jadeite, concrinite, cordierite, lapis lazuli, lepidolite, lepidomelan, murmanite, nitrolite, nozeam, pyroxenite, plagioclasm, feldspar, ribenite, sodalite, phlogdin. It is advisable to use the iron compound in the form of oxides, silicates, alkaline ferrosilicates, alkaline aluminosilicates, which are introduced in the mixing step. It is possible at the mixing stage to additionally introduce alkaline salts, for example, soda, potash in an amount of 1-10 wt.%. The essence of the method is that to increase productivity, an increase in the rate of decomposition of the phosphate feed is required, which can be achieved by the following processing methods. The thermal decomposition of phosphate feed is accompanied by the formation of a certain amount of melt, which proceeds as follows: dissolution of phosphates in the melt, diffusion of water vapor into the melt, diffusion from the solution of the resulting HF and SiF4, crystallization from the melt of the final high-temperature product in the form of tricalcium phosphate, potassium sodium phosphate, phosphate, in the structural lattice of which silicon also enters. Ferrous iron, which is added in the form of various compounds, changes the physicochemical properties of the melt, namely, reduces its viscosity, surface tension, etc. As a result, the speed of the first stage associated with the dissolution of phosphate in the melt increases, which speeds up the process of preparation final product. At the same time, the dispersion of the phosphate raw material has little effect on the productivity of the process. Ferric iron in such a system is an oxidizing agent relative to ferrous iron, which is capable of delivering oxygen to the system in an ionic melt. In this case, the speed of the process of defluorination (and hence decomposition) of the phosphate feed increases due to the replacement of fluorine with oxygen by the reaction: POF2 + - PO + H + Thus, ferrous iron accelerates the decomposition of the phosphate feed due to the physicochemical properties of the melts and increases the mobility of ions in the melt, and ferric iron - by increasing the reaction rate of the formation of the final gaseous product HF. The presence of ferrous and ferric iron in a ratio of 0.05-10 makes it possible to increase the overall speed of the process. An increase in the process speed due to the use of ferrous and trivalent iron contributes to a change in the physicomechanical properties of the product, which increases the yield of the product fraction from the rotary kiln. This is due to the fact that with an increase in the decomposition rate, the melt is consumed faster as a result of interaction with phosphate to form (crystallize) the final high-temperature compound (product). Since this interaction is accelerated, the material to the high-temperature zone of the furnace, where the maximum heat generation from the combustion of fuel occurs, is more heat-resistant, which prevents rolling the material into granules and pieces and increases the yield of marketable products. The presence of alkaline salts in the raw material mixture allows the production of high temperature calcium sodium phosphates, which crystallize well from the melt, thereby increasing the yield of the product fraction. Thus, in order to provide the required amount of the obtained product and the productivity of the production line, it is necessary to create the conditions set forth in the invention. The effect of the amount of ferrous and ferric iron added on the process productivity and the yield of the product fraction of the product is presented in Table. 1. In

The alkali metal aluminosilicates used were nepheline, glacuonite, Porevich spar, ratio 3.0.

With the addition of ferrous and ferric iron of less than 0.5% by weight, productivity decreases due to a decrease in the rate of decomposition of phosphate. As a result, the material approaches the high-temperature zone with an excess of melt, which causes it to pelletize and reduce the yield of the product fraction of the product. When ferrous and ferrous iron is added in excess of 6.5%, the feed mixture in the furnace becomes refractory, begins to clump, which in turn reduces the diffusion of water vapor in the material, as well as HF from the material, while the yield of the product fraction decreases sharply. The effect of the ratio between the ferric and ferric iron is given in table. 2. Nepheline, feldspar, and glacuonite were used as aluminosilicate.

less than 0.05 lower

The process speed is due to insufficient oxygen in the melt, which accordingly causes a decrease in the yield of the commercial fraction. With respect

Fe3 +

 over 10 the process speed remains

Fe

the output of the product fraction remains almost unchanged, unchanged, since from F

 10 provides

wearing

the furnace’s duration was 6.0 t / h, the output of commodity fg) shares was 70%.

An example of 2.1000 kg of fossyr is mixed with 100 kg of nepheline containing 2% iron oxides relative to the weight of nepheline, iron oxides are added to obtain ferrous and ferric iron in an amount of 6.5% and the ratio

.3 +

Fe 10, the resulting mixture is moistened to co2-1Fe

0

keeping humidity 30%, it is calcined in a rotary kiln. The furnace productivity is 8 t / h. The output of the commercial fraction is 78%. Calcination was carried out at T 1400 ° C and excess air. 2. Example 3. 1000 kg of fossyr are mixed with 100 kg of nepheline containing 2% iron oxides relative to the weight of nepheline, iron oxides are added to obtain ferrous and trivalent iron in coF

0% 3.5% and ratio c; 3.0,

fe

the resulting mixture is moistened to a moisture content of 30%, fired in a rotary kiln at T 1400 ° C and excess

5 air ct 1.2, The furnace productivity was 7.0 t / h, the yield of the product fraction of the product was 74%.

Example 4. 1000 kg of fossyr are mixed with 100 kg of nepheline containing 2% iron oxide relative to the weight of nepheline, and iron oxides in an amount of 3.5% are added to iron oxides to obtain ferric and ferric iron in an amount of 3.5

p 3-h May 5. % and a ratio of -5T 3.0. received

SL

best process performance.

The effect of alkaline salts on process indicators is presented in table. 3. The amount of ferrous and trivalent iron is 3.5%, from Fe + wearing is 3.0.

7

The use of soda in an amount of less than 1.0% does not change the performance of the process. The use of soda over 10% is impractical, since the process indicators remain unchanged.

Example 1. 1000 kg of fossyr is mixed with 100 kg of nepheline containing 2% iron oxides relative to the weight of nepheline, additional iron oxides are added in such an amount that the total amount of Fe is 0.5 wt.%, Aotnorez + gt; 0.05. The resulting mixture uvFe

cuddle to a moisture content of 30%. calcined in a rotary kiln at a temperature of 1,400 ° C and an excess of air of 1.2. The mixture is moistened to a moisture content of 30%. fired in a rotary kiln at T 1400 ° C and an excess of air o: 1.2, The furnace productivity was 7.7 t / h, the yield of the product fraction was 84%.

Example 5. 1000 kg of fossyr is mixed with alkaline aluminosilicate (glauconite), in an amount of 3.2 wt.% Until the ferrous and ferrous iron are obtained in the raw material mixture and the ratio

 2.9.

the resulting mixture is fired in a rotary kiln. The furnace productivity was 6.5 t / h, the yield of the product fraction of the product was 70%.

Example 6. 1000 kg of fossier is mixed with alkaline aluminosilicate (glauconite), in an amount of 3.2 wt.%, To obtain in the raw material mixture of ferrous and ferrous iron, and the ratio

Claims (4)

1. A method of producing feed and fertilizer phosphates, including mixing phosphate raw materials with aluminosilicate minerals, moistening the mixture, firing the mixture at 1350-1500 ° C with the supply of excess air, characterized in that, in order to increase the productivity of the process and increase the yield of commercial fraction , firing is carried out in the presence of a mixture of ferrous and ferric iron compounds, which is added in an amount of 0.5-6.5 wt.% at a weight ratio of 0.05-10. 2. The method of pop, 1, characterized in that as aluminosilicates are used 3 yut nepheline, e g and r and u. albite, analcime, arfvedsonite, astrophyllite, biotite, vermiculite, glauconite, muscovite, orthoclase, microcline, jadeite, concrinite, cordierite, lapis lazuli, leucite, lepidolite, lepidomelan, murmanite, nitrolite, noceam, pyroxenite, pliregenite, plungite, plungite, plungite, plungite, plungite, plungite, plungite, plungite , sodalite, phlogonite, zeolites, cynvaldite, equidialite. 3, The method according to claims 1 and 2, characterized in that the iron compounds in the form of oxides, silicates, alkaline ferrosilicates, alkaline aluminoferrosilicates are introduced in the mixing step. 4. The method according to paragraphs. 1-3, characterized in that at the mixing stage soda is additionally introduced, potash in an amount of 110 wt.%. Table 1 table 2 12.5 8.0 78 Table 3 12 9.0 8G