SU1599304A1 - Method of producing magnesium oxide or products of hydration thereof - Google Patents

Abstract

The invention relates to the production of magnesium compounds and can be used for the production of magnesium oxide and its hydration products used, for example, in the production of refractory materials, in the electrical and pulp and paper industry, in construction and in the production of rubber. The starting product, which is a mixture of magnesium and calcium oxides, for example calcined dolomite, is treated with an aqueous solution containing one or more organic nitrogen-containing compounds and a salt of these compounds with an acid that can form a water-soluble calcium salt. Monoethanolamine, diethanolamine, piperidine or ethylenediamine and, respectively, their salts with hydrochloric, nitric, formic and acetic acids are used as nitrogen-containing compounds. The residue remaining after treatment is magnesium oxide with a calcium oxide content of less than 1% by weight. Expediently, the resulting mother liquor is subjected to regeneration with carbon dioxide at pH 7-12, the precipitated calcium carbonate is separated, and the regenerated solution is used at the stage of processing the primary raw material. 1 hp ff.

Description

This invention relates to the production of magnesium compounds and can be used to produce oxide.

. . Magnes and its hydration products, used, for example, in the production of refractory materials, in electrical and cellulose-paper formation, in construction and in the production of rubber.

A known method for producing oxide

. magnesium (autor. Czechoslovakia No. 190976, yut. C 04 and 35/20, 1978), in which .. a mixture of oxides of magnesium and calcium, forming with dolomite after roasting

above, treated with acid or nitrate, ammonium formate or acetate.

However, this method only partially removes calcium oxide and the resulting product contains more than 20% by weight. hydroxy and calcium.

The closest to the present invention is a method for producing magnesium oxide (ed.St. NRB No. 34659, class C 01 F 5/06, 1983), in which calcium oxide is leached from a mixture of calcium oxides and magnesium obtained in calcining dolomite by processing

Q1

with

with

 ABOUT

N

its sugar solution at a molar ratio of calcium oxide to sugar I (1: 1, 1) - (1: 1.3) for 2 hours. The remaining precipitate is separated from the solution,

(treated with dilute acidic acid, washed and dried. The product obtained contains more than 97% by weight of magnesium oxide.

However, this method is of little use for progressive use, since a solution of sugar, a valuable food product, is used as a leaching agent. In addition, sugar in solutions is destroyed under the influence of microorganisms, its solutions (have relatively high viscosity. This makes difficult the practical use of these solutions and, above all, their regeneration and recycling.

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I The essence of the proposed method is that the starting product is a mixture of oxides of magnesium and calcium, for example calcined dolomite, is treated with a solution containing one or more organic nitrogen-containing compounds 1N and a salt of the above compounds with such an acid: which is itself capable of forming a water-soluble calcium salt. These acids include: salt, nitric, formic, and acetic acid. The specified solution is selectively better: bakes calcium oxide from the mixture by reaction

MgO xCaO + ZxAB + xH-iO-MgO + xCaA 2 + 2хВОН where x is the number of moles of oxide of a capita per mol of magnesium oxide;

And - anion of monobasic acid; B - cation of organic nitrogen,

holding compound;

AB is a salt of a nitrogen-containing compound with an acid; VON - organic nitrogen-containing

compound.

The precipitate, consisting mainly of magnesium compounds, is separated from the mother liquor, poured on and dried. The mother liquor is advisable to regenerate carbon dioxide by the reaction: - CaA, + 2BOH4-C02 -CaCO, + 2AB.

After separation of the precipitated carbonate, the al ys regenerated

the solution can be recycled to the stage of processing the feedstock.

In order to completely isolate the calcium component from the regenerated solution, the regeneration process is carried out at a pH of 7-12 and with an excess amount of organic nitrogen-containing compound compared with a stacking amount corresponding to the structure of the AI.

Example 1. 100 mach. dolomite containing,.%: CaO 30.81; MgO 21.33; 810gO, 32; burned at. The weight loss during calcination is 47.10 wt.%. After firing, the agglomerate is ground and sieved through a sieve with openings of 0.06 mm in size. Then, to the resulting mixture with continuous stirring, gradually up to 600 mas. an aqueous solution with a temperature containing 120 May, h. mono-ethanolamine and 50 ma.ch. monoethanol amine The resulting suspension is stirred for 1 hour. After that, the insoluble precipitate is separated by filtration from the mother liquor heated by the reaction heat to 30 ° C. From the solution cooled to 30-40 ° C, precipitated with carbon dioxide after reaching pH 8 carbonate, filtered it is washed and dried. 52 ma.ch. Calcium carbonate, containing 99.6 May,% CaO B. c., after firing, which corresponds to 95% of calcium oxide contained in the raw material. The precipitate separated from the mother liquor is also washed and dried. It contains, wt%: MgO 96.65; CaO 0.31; SiOg 1.35; A12.0e 0.83; 0.85 (in the state after annealing),

Example 2. The process is carried out analogously to example 1. The initial dolomite contains, in May,%: CaO 30; MgO 27.67; SiOi, 0.15; Al, 0g 0.02; 0.03, the mass loss during calcination, which is carried out at, is 47.50%. The calcined and crushed portion is suspended at 300 mash. the solution and in the resulting suspension add another 300 May, h. an aqueous solution with a temperature of 60 ° C, containing 150 ac, h, monoethanolamine acetate and 50 May, h, monoethanolamine. Calcium carbonate is obtained from the uterine regimen after separation of the non-dilutable sludge and treatment with carbon dioxide.

.1599304

with a content of 99.5 wt.% CaCO ,. In vi-1.85 wt.% CaO, burn gfy.

de carbonate calcium extract 94% weight loss during calcination composition

calcium oxide in the raw materials. The insoluble precipitate containing predominantly magnesium oxide and its hydration products, after washing and drying, contains, in wt.%: MgO 97.68; .CaO 0.92; SiOiO, 76; A12.0eO, 9; 0.24. (In terms of the condition after calcination).

Example 3. To 100 ma.h. baked and crushed dolomite, containing, wt.%: CaO 58.31; MgO

lt is 52.15%. Burnt magnesite is shallow and sieve through a sieve as described in Example I. The resulting product is treated with 500 mash. a solution containing 60 wt.h. ethylene diamine acetate and 20 wt. diethanolamine, 10 with stirring for 1 hour. Then, a non-solvent) precipitate is separated from. the solution is filtered and pass through desalted water. The composition of the precipitate after calcination, wt.%: MgO 96,85;

41.25; SiOa. 0.32; and 5 CaO 0.35 f SiOg 0.70; AljjO 0.55;

Fe.jOa 1.25, The remaining solution is regenerated by passing a current of carbon dioxide.

Example 6. By 100 May. including obo 05, add 12.00 May, h. an aqueous solution with a temperature of 20 s, containing 280 May, h. piperidine chloride and 30 ma.ch. Monoethanol amine. After stirring the resulting suspension in dolomite at 2050 ± 50 ° C for 1 h from a solution heated heated, wt.%: CaO 78.15; MgO 20.25; stock heat up to 50 С, filtered- SiO, 2.Q, 30; , 0.25; , 1.05, a solid precipitate is formed, 1400 wt.h. is added after grinding.

mainly from magnesium oxide and an aqueous solution containing it. hydration, washed it and 25 360 ma.ch. monoethanolamine nitrate, dried. The precipitate after roasting contained pieces, 15 mach. magnesium nitrate and 20 mah.

wt.%: MgO 97,69; CaO 0.94; Si020.81; monoethanolamine. Suspension, heating - Alj, 03 0.22; . The remaining reaction heat before the precipitate separates the mother liquor is stirred for 1 h, then the non-TBQP is treated with carbon dioxide. ZO, the reacted precipitate containing. Calcium oxide formed. After reaching magnesium oxide and its hydration products pH 7.5, it is filtered, filtered, filtered and dried. Receive 100 mach.ch. carse. The filtered calcium carbonate product containing 99.2% by weight is carbon dioxide and does not convert CaCOj, which corresponds to 97% of the leached calcium oxide to calcium carbonate in the feed. The resulting product contains 1st

Example 4, 00 mac. burned- mostly hydrated

magnesium oxide and calcium carbonate, is used, for example, in the steel foundry industry. It contains after annealing, wt.%: TigO 85,10; CaO 7.7 0; SiOa. 1.20; 1.15; 4.60.

Through remaining after filtration

ground and crushed caustic calcinate of magnesite containing, wt.%: MgO 88.5; CaO 7.2; SiO 3.5; Al-jOj 0.4; , treated with stirring for 300 May, h, an aqueous solution containing 30 May, h, monoethanol formate # 1 on May 3, h, monoethiiodine for 1 h. Then the non-solution dissolves soluble solid phase at 60 ° C the carbon filter, the precipitate formed is carbonated, washed with water and dried. The composition of the sediment after calcination, wt.%:

MgO 95.4; CaO less than 0.1; SUD 3.7;

The calcium is filtered off, washed with water and dried, and the remaining regenerated solution is suitable for. and 0.4. The remaining recirculation to the processing stage of the solution is treated with carbon dioxide, a feed stock.

then formed when

this monoethanolamine carbonate add-g

stoichiometric amount

calcium formate, separated by formation of 55

Shiys precipitate CaCOj and recirculate.

Claims (2)

Invention Formula . stage of processing of raw materials. PRI me R 5. 100 may, h magnesite containing 45.10 wt.% MgO and 1, Method for the production of magnesium oxide and / or its hydration products, including the treatment of calcined dolomite at a temperature of 0-100 ° C with an aqueous solution of organic matter, lt is 52.15%. Burnt magnesite is shallow and sieve through a sieve as described in Example I. The resulting product is treated with 500 mash. solution containing 60 mash. ethylene diamine acetate and 20 wt. diethanolamine, 10 with stirring for 1 hour. Then, a non-solvent) precipitate is separated from. the solution is filtered and pass through desalted water. The composition of the precipitate after calcination, wt.%: MgO 96,85; , 5 CaO 0.35 f SiOg 0.70; AljjO 0.55; CaO 0.35 f SiOg 0.70; AljjO 0.55; Fe.jOa 1.25, The remaining solution is regenerated by passing a current of carbon dioxide. Example 6. By 100 May. h. burned at 1050 ± 50 С dolomite, containing, wt.%: CaO 78.15; MgO 20.25; SiO, 2.Q, 30; , 0.25; , 1.05, after grinding, 1400 mash are added. Invention Formula 1, Method for the production of magnesium oxide and / or its hydration products, including the treatment of calcined dolomite at a temperature of 0-100 ° C with an aqueous solution of organic matter, separating the precipitate from the mother liquor, washing the precipitate and drying it, about t;; characterized in that the processing of the raw material is carried out with an aqueous solution containing monoethanolamine and / or diethanopamine and / or piperidine and / or ethylene diamine and salt of these substances with hydrochloric, nitric, formic and acetic acids. Editor N.Kkpatulinets Tehred L. Oliynyk Order 3116 Circulation 404Subscription VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology CCCF 113035, Moscow Zh-35, 4/5 Raushsk Nab. Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101 2. The method according to claim 1, wherein m and y - and so that the mother liquor is subjected to regeneration with carbon dioxide at pH. 7-12, the precipitated calcium carbonate is separated, and the solution remaining after separation of the precipitate is recycled to the feedstock processing stage. Proofreader S. Tsipl