SU1699986A1 - Method of processing magnesium-bearing phosphate stock - Google Patents

Abstract

The invention relates to a technique for the processing of phosphate fertilizers, the production of magnesium oxide from magnesium-containing phosphate raw materials and contributes to the involvement of phosphate raw materials with a MgO / P Og1 SOO ratio of 30-90% (waste thermo-separation phosphate raw materials), improving the quality of magnesium oxide and creation of low-waste technology. For this, the phosphate raw material is treated with sulfuric acid to the content of magnesium oxide in the liquid phase of the suspension of 2.0–3.8%, the suspension is filtered and the filtrate is treated with ammonia and carbon dioxide or ammonium oxalate or ammonium carbonate at pH 4.5–7.0 and ignite the resulting product to obtain an impregnation of at least 967 MyO. The implementation of the process by the proposed method allows to significantly improve the quality of magnesia, to include in the processing of magnesium-containing phosphate raw materials with the ratio of MgP fV 1 00 - 30-90% (waste Thermgs ePoG-donor enrichment of the phosphate raw materials), to create low-waste technological ip due to regeneration of neutral ui: ..: r about the vvr., .-., (1. p. gachov, possessor of gmmnai and gshch at the 1.4er-one, and return them to the LTII.. .- other process. 1. and. , 2 An.1. С Ј and with & S & co with 00 O

Description

This invention relates to a technique for the processing of phosphate fertilizers and the production of magnesium oxide from magnesium-containing phosphate raw materials.

The aim of the invention is to combine low-waste tichiolmgy, to improve the quality of Mai oxide, either by increasing the content of the basic substance in the nominal mixture and preserving the quality of the phosphoric carbon i i

increase recovery 1 F 1Sfatnych end ntrg-t.

 r i me r 1. 10 (HI mat nipso- jjep aruero prelude .- .: eaten phosphate raw material. (. - ". Pvoct napa- pononnot aboutioi asheni), cii-np lanch o, h. 7: R.2. 17.1; CaO 2 (-, (;:. ЦО .15,0 (from. Mpn / P ib. | iti -

- PO.CH. IPT G. STALI; SUE - PONY,

I .iv.) AiG, 1, and LF (| and

3D min 276.5 kg of working solution and 65 kg of 50% sulfuric acid. The degree of extraction of magnesium in the solution is 90%. The obtained 441.5 kg of the suspension is fed to a filter where 86.5 kg of the demagnetized phosphate raw material, containing about 20% P20, 31% Ca ° and 1 7% m °, is separated. The demagnetized phosphate raw material goes to the extraction stage. where it is treated with 52 kg of 92% sulfuric acid and 389 kg of circulating phosphoric acid. Then, 527.5 kg of pulp is filtered, named 158.5 kg of water and receive 81 kg of production phosphoric acid with a concentration of 20%, 389 kg of turnover — I | OH of phosphoric acid returned for extraction, and 216 kg of phosphogypsum with a humidity of 40%; in the fall, the resulting extraction phosphoric acid is concentrated and neutralized with ammonia to obtain 48 kg of Ammophos, which meets the requirements of m.

In addition to the demagnetized phosphate, the raw material from the filtration stage removes and neutralizes 355 kg of magnesium-coder .ai i /: ro filtrate (3.8% MgO), which is treated in the neutralizer with 42 kg of ammonium oxalate until the pH reaches h, 5; In this case, magnesium oxalate precipitates, which is separated on the filter Kpri filtration capacity (850 kg / m2-h). The resulting 37.8 kg of magnesium oxalate is calcined at 900 ° C and 14 kg of production production of Magnesium with a MgO content of 97% is obtained. After the separation of magnesium oxalate, the filtrate is sent to the decomposition stage as a working solution.

Example 2. 100 kg of pre-washed washed magnesium-containing phosphate raw material (waste thermal separation enrichment), containing, wt.%: 16.7; CaO 26.3; MgO 10.0 (MgO / P20 100 60% ratio), is fed to the decomposition stage, where 402 kg of working solution and 49 kg of 40% sulfuric acid are treated at 90 ° C for 20 minutes. The degree of extraction of magnesium is 92%. The resulting 551 kg of the suspension is separated on a filter to obtain 460 kg of magnesium-containing filtrate (2% MgO) and 91 kg of phosphate-free phosphate-free raw material containing 18.47 P.1 28.9% CaO and 0.9% MIO.

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phosphate raw material enters the extraction stage, where it is treated with 410 kg of circulating phosphoric acid and 63 kg of 75% sulfuric acid. Then, 564 kg of phosphogypsum pulp are separated on a filter, the precipitate is washed with 166 kg of water and 235 kg of wet (42% humidity) phosphogypsum is sent to the dump. 410 kg of circulating phosphoric acid are returned to the extraction stage, and 85 kg of production acid (19% of phosphoric acid is concentrated, neutralized with ammonia, and 51 kg of ammophos, corresponding to the requirements, are produced.

460 kg of magnesium-containing filtrate is removed for neutralization, where it is treated with gaseous ammonia (4 kg) and carbon dioxide (5 kg) to pH 7. The resulting suspension of magnesium hydroxycarbonate (469 kg) is separated on a filter (filtration capacity 600 kg / m2.h ) to obtain 16 kg of magnesium hydroxocarbonate, which is calcined at 900 ° C to obtain 9.6 kg of production magnesia (MgO content 96%) and 453 kg of filtrate fed to the ammonia regeneration step. During the calcination of magnesium hydroxocarbonate, 4.4 kg of carbon dioxide is released into the gas phase, which, after feeding 0.6 kg of fresh carbon dioxide, is fed to the neutralization stage. As a result of regeneration, 3.7 kg of ammonia and 47.3 kg of water vapor are released into the gas phase. After feeding 0.3 kg of fresh ammonia, it is also fed to the neutralization stage. So get a closed loop neutralizing agents. 402 kg of the solution after the ammonia regeneration stage is sent to the decomposition stage of the starting phosphate raw material as a working solution.

Example 3. 100 kg of pre-washed magnesium-containing phosphate raw material (waste of thermal separation enrichment), containing, in wt.%: Pg05 16.1; CaO 24.7; MgO 4.8 (MgO ratio (100 - 30%), is fed to the decomposition stage, where 125 kg of a working solution and 22 kg of 45% sulfuric acid are treated at 90 ° C for 25 min. 91%; 247 kg of the suspension obtained is separated on a filter to obtain 151 kg of magnesium-containing

(2.9% MgO) and 96 m of phosphate free raw material containing 16.8% of 25.3% CaO and 0.5% MgO. The non-magnetized phosphate feedstock enters the extraction stage, where it is treated with 348 kg of recycled phosphoric and 58 kg of 75% sulfuric acid. Then, 502 kg of phosphogypsum pulp is separated on a filter, the precipitate is washed with 1b3 kg of JQ water and 232 kg of wet (40% moisture) phosphogypsum is sent to the dump. 347 kg of circulating phosphoric acid is returned to the extraction stage, and 85 kg of production (18% P) F ° C 15 (fororic acid is concentrated, neutralized with ammonia and 51 kg of ammophos are obtained, the corresponding requirement of 151 kg of magnesium-containing filtrate is diverted to neutralization, where 20 is worked up with a 40% ammonium carbonate solution (13 kg) to pH 6. The resulting suspension of magnesium hydroxocarbonate (164 kg) is separated on a filter (filtration capacity 25,650 kg / m2 (h) to obtain 8 kg magnesium magnesium calcined. three 900 ° C to obtain 4.6 kg of production magnesia (MgO content of 96.5%) and 156 kg of filtrate, the quality is obtained within the limits of the parameters. During the process, neutralization of the solution at-values of 4.0 solid phase ш is formed, and at (4) precipitation from ammonium lettuce does not occur, therefore, high-quality magnesia is not obtained.

When carrying out the process of neutralizing the magnesium-containing solution at pH 7.1, excess consumption of the reagent begins. partial release of ammonia and carbon dioxide into the gas phase; no stable sodium hydroxycarbonate compound is formed and the goal is not achieved.

When carrying out the neutralization process at RP 9.0 and above, the complete dissolution of magnesium hydroxycarbonate occurs with the release of ammonia and the finished product is not formed.

The substantiation of the effect of the trait, including the processing of the raw material of sulfuric acid to a content of 2-3.8% MgO, on the quality of the products obtained from the processing of phosphate raw materials is presented in Table. 2

As can be seen from the data table. 2, when carrying out the process in the proposed

within the parameters, quality is obtained. When carrying out the process of neutralizing Mamshim solution with a value of 4.0 solid phases is formed, and at (4) ammonium lettuce does not precipitate, because it does not achieve high-quality magnesia.

When carrying out the process of neutralizing the magnesium-containing solution at pH 7.1, excess consumption of the reagent begins. partial release of ammonia and carbon dioxide into the gas phase; no stable sodium hydroxycarbonate compound is formed and the goal is not achieved.

When carrying out the neutralization process at RP 9.0 and above, the complete dissolution of magnesium hydroxycarbonate occurs with the release of ammonia and the finished product is not formed.

The substantiation of the influence of the trait, including the processing of the raw material of sulfuric acid to a content of 2-3.8% MgO, on the quality of the products obtained from the processing of phosphate raw materials is presented in Table. 2

As can be seen from the data table. 2, when carrying out the process in the proposed

giving to the stage of regeneration of ammonia. Upon calcining the magnesium hydroxocarbonate and the gas phase, 2.2 kg of carbon dioxide and 1.2 kg of water vapor are released, which return to the -35 neutralization cycle of the magnesium-containing solution. As a result of regeneration, 1.6 kg of ammonia and 29.4 kg of water vapor are released into the gas phase, which are returned to the neutralization cycle 40 of the magnesium-containing solution. After impregnation with fresh ammonium carbonate solution, this solution enters the neutralizer. Thus, a closed loop is obtained for neutralizing there. 125 kg of the solution after the ammonia regeneration stage is sent to the decomposition stage of the initial phosphate feedstock as a working solution. -Q

Justification of the limits of the proposed parameters of the process are given in Table. one .

As can be seen from the data table. 1, when carrying out the process in the proposed, within the limits of the parameters, the content of MgO and calcined propelste is 96-97% 5, whereas, as for the erect conditions, this value does not exceed M.

Chemical products: ammophos and magnesium oxide.

When carrying out the process of processing raw materials with sulfuric acid to the MgO content in the liquid phase of the suspension to 16.9%, it is not possible to obtain ammophos, which meets the requirements, this reduces the content of mustache form, Ј. and the content of impurity components increases (due to the deterioration in the quality of the extraction phosphoric acid). In addition, the quality of the magnesium oxide in the yield of magnesium oxide is controlled by the neutralization of the magnesome solution.

When processing the raw material with segmented acid to the MgO content in the liquid phase of the suspension to 3.9, the goal is not achieved due to the increase in IV losses (, increasing the content of impurity components, reducing the yield of ammophos, deteriorating the quality of ammophos. The N-agnium-containing solution appears to imply a decrease in the quality of magnesium oxide by the addition of a mixture of KOMHOHOHVOB impurity impurities KOMHOHOHVOB 7 tr; g neravral solution i. The content of magnesium-i does not exceed 0.

Thus, the implementation of the proposed method creates the possibility of processing but low-waste technology of the effect of low-quality phosphate raw materials (waste of thermal separation phosphorite enrichment with simultaneous obtaining of qualified magnesia.

Formula of Invention

Claims (1)

1. Method of processing magnesium phosphate phosphate feedstock phosphate fertilizer and magnesium oxide, which includes treating the feedstock with sulfuric acid, filtering the resulting slurry and forming a phosphate concentrate that is processed into fertilizer and magnet filtrate, processing the filtrate with a neutralizing agent, separating it from the resulting suspension of solid product and proc five 0 casting it, characterized in that, in order to create low-waste technology, to improve the quality of magnesium oxide by increasing the content of the main substance in it and to maintain the quality of Phosphate fertilizer by increasing the recovery to phosphate concentrate during the processing of phosphate raw materials with a ratio of MgO / Pz05 100 % 30-90%, processing of the raw material is carried out until the content of magnesium oxide in the liquid phase of the suspension is 2–3.8%, compounds containing ammonia and carbon dioxide are used as neutralizing agent, and treatment with neutralizing agent is used until a pH of 4.5-7.0 is reached. 2, the method according to claim 1, about tl and h a rout and also with the fact that ammonia and carbon dioxide or ammonium oxalate or ammonium carbonate are used as neutralizing agent. Table 1 table 2