SU1798300A1 - Charge for agglomeration phosphate raw materials - Google Patents

Description

The invention relates to a technology for the preparation of phosphate raw materials for electrothermal production of yellow phosphorus.

The aim of the invention is to increase the content of phosphorus oxide in the finished product while ensuring its high strength.

A significant difference is offered; The first invention from the prototype is the introduction of a fluxing additive into the phosphate fines, represented by lime sludge. with the following ratio of components. May. %:

Lime sludge 15-30

Phosphate raw materials 70-85

This difference makes it possible to increase the coefficient of porosity and the content of P2O5 in the finished product.

Lime sludge is a waste of phosphorus production and has a chemical composition, May. %:

P2O525-35

CaO25-35

SiO2 30 - 35

F4-6 rest water

This is a finely dispersed material (the content of the fraction minus 0.074 mm is 75-80%).

Phosphate fines is a waste of phosphorus production, formed during the extraction, transportation and technological redistribution of phosphorites. In the proposed method, phosphate fines are used that meet the specifications TU 113-12142-88 class M.

Phosphate fines are used in crushed form (the content of the fraction minus 0.074 mm is 60 - 65%).

EXAMPLE A dry charge consisting of phosphate fines and a fluxing additive of lime sludge at the following ratio, May. %:

Lime sludge 22

Phosphate raw materials 78 are mixed in a drum mixer for 2 minutes, moistened to a water content of 10% and pelletized on a disc granulator with a diameter of 1.0 m at an angle of inclination of 40 degrees, and a speed of 18 rpm. 5 The raw pellets are dried at a temperature of 1050 ° C for 25 minutes. Under these conditions, the porosity is 22%, the product yield is 97.3, and the P2O5 content is 27.82. pellet strength 420 kg / pellet, Yu

The data are summarized in a table.

As can be seen from the table, the optimal porosity and high content of P2O5 in the finished product is achieved with the following content of components in the charge, May. %: 15 lime sludge 15 - 30, phosphate fines 70 - 85 (examples 1-5).

An increase in the content of lime sludge more than 30% (examples 7, 8) leads to a decrease in the strength of the agglomerated phosphate material due to an increase in volatile gaseous components.

A decrease in the content of lime sludge below 15% (example 1) leads to a decrease in the content of P2O5 and the yield of the finished product, due to a decrease in the porosity of the agglomerated phosphate material.

The proposed method in comparison with the prototype (examples 9-13) allows you to increase the porosity by 1.3 times, and the content of P2O5 in the finished product by 1.17%. In addition, during firing, the gas dynamics of the firing process improves, which, in turn, halves the firing time and makes it possible to solve an urgent environmental problem - the processing of solid waste (lime sludge) obtained by neutralizing acidic and phosphorus-containing waters in the water consumption system, as well as allows you to involve in the production of phosphate fines.

Claims (5)

Claim A charge for agglomeration of phosphate raw materials, containing a fluxing additive and phosphate raw materials, is hot because, in order to increase the content of phosphorus oxide in the finished product while ensuring its high strength, lime is used as a fluxing additive. sludge of phosphorus production at the following ratio of components, May. %: Lime sludge 15-30 Phosphate raw materials 70 -85. Example Fluxing additive content Phosphate raw material content,% Containing? the addition of P2O5 in the finished product. % Product output ta, ^ Strength, kg / pellet Porosity,% lime sludge content,% carbonaceous shale and acidic phosphate salt sludge,% ' 1 ¹⁵ - ^: 85 26.2 96.4 380 18.5 2 twenty - 80 27.1 97.2 410 21.3 3 22 - 78 27.82 98.0 442 22.2 4 25 - 75 27.8 97.4 420 24.1 5 thirty 70 26.5 96.3 400 29.4 d. Outrageous values' 6 ten - · 90 24.9 95.8 360 15.0 7 35 - 65 25.4 96.0 370 37.4 eight 40 - 60 24.1 94.8 340 38.1 Table continuation Example Content of fluxing additive Content of phosphate raw material,% Content of P2O5 in the finished product,% Product yield, ¹ ^ Strength, kg / pellet Porosity,% content of lime sludge,% carbon-containing shale and acidic phosphate salt sludge,% Prototype nine -G' 2.4 97.6 23.3 96.8 410 15.4 ten - 3.0 - 97.0 23,7 97.2 442 16.1 eleven - 3.6 ' 96.4 22.9 96.8 420 16.8 12 -. 1.8 98.2 23.2 95.2 .386 14.0 13 - 4.2 95.8 2'2.9 '' 96.0 390 14.2