CS210818B1

CS210818B1 - The method of mechanical-thermal activation of magnesium raw materials

Info

Publication number: CS210818B1
Application number: CS136679A
Authority: CS
Inventors: Jozef Haessler; Mirek Filak; Juraj Haessler
Original assignee: Jozef Haessler; Mirek Filak; Juraj Haessler
Priority date: 1979-03-01
Filing date: 1979-03-01
Publication date: 1982-01-29

Abstract

Vynález sa týká spósobu mechanicko-termickej aktivácie horečnatých surovin pre rozklad úcinkom slabých kyselin, alebo solí.The invention relates to a method of mechanical-thermal activation of magnesium raw materials for decomposition by the action of weak acids or salts.

Description

SOCIALISTIC AND DESCRIPTION OF THE INVENTION

l ”'TO COPYRIGHT 210818 (11) (Bl)

(22) Registered 10 08 79 (21) (PV 5467-79) (51) others. Cl.3C 09 C 3/04 (40) Published 29 08 80

OFFICE OFFICE (45) Published 15 09 83

AND DISCOVERY (75)

The inventor

TKÁČOVÁ KLÁR RNDr. CSc., HOCMANOVÁ IRENA Ing., CSc., KOŠICE (54) Mechanic-thermal activation of magnesium raw materials 1

The invention relates to a method of mechanically-thermal activation of magnesium raw materials for the degradation of weak acids or salts.

The slipping stage of the various chemical treatment procedures is the decomposition of the feedstock and the conversion of the useful component into solution. In the case of magnesium raw materials, the decomposition is based on the reaction of cation β anionic acids to form soluble magnesium salts. The present technology utilizes heterogeneous reactions at the solid-liquid interface to decompose the magnesium component into an aqueous solution. In so-called basic technologies, lye-rich or weak acids such as bicarbonate technology, see literature: Packages CJ: Developments in Magnesium Production and Fabrication B ·. J. 0. S. No. 1,338; HegrailG .: US Patent No. 264,381, 1953; Gann JA: Ind. Eng. Chem. 22, 694 (1930), for the modified technologies of their salts, eg modified nitrate technology, see literature: Jerman, Kyznárová: Report of the Research Institute of Inorganic Chemistry in Ústí nad Labem No. 800, 1975; butbodified Solvay technology for the production of soda and magnesium oxide, see literature: Cheese combine based on magnesite and salt. Technical and economic studies. Directorate GeneralSiovchémía Bratislava 1977.

Some modified technologies use a heterogeneous reaction at the interface of two solid phases to decompose, followed by leaching of the magnesium component from a solid product, eg modified sulfate technology, see literature: Prokleška F., Šťastná M .:

Utilization of waste green rock by thermal decomposition with magnesite. Final Research Report »No. 244-805, Institute for Ores Research Mníšek pod Brdy 1974. The favorable course of decomposition and leaching is conditioned by solid phase activation. Especially challenging for activation are modified chemistry treatments that require high reactivity of feedstock. Activation of magnesium-containing carbonate-type materials, eg magnesite, dolomite, is currently carried out by thermal means, ie by causticisation. firing.

The above-mentioned disadvantages are substantially eliminated by the invention.

The invention is based on the fact that the carbonate-type magnesium raw material, e.g. magnesium, dolomite, is fired at a temperature of 500-800 [deg.] C. and at the same time as the firing, or the subsequent firing, has a grain size distribution characterized by at least 70% finer proportions. 20 microns.

It is an advantage of the invention that the mechanical raw materials activated by mechanical-thermosensor reactivity, the rate of leaching of these materials is greater, and the limiting yield of the magnesium solution is 15 to 25 percent higher than in the extraction of raw materials activated by conventional thermal processes.

The favorable influence of the reactivity of the magnesium raw materials by mechanical-thermal means allows the leaching of less valuable magnesites by solutions of weak acids and salts and reactivation of the precipitated materials whose reactivity has decreased in the course of aging. In the light of the above-mentioned advantages, it is possible to carry out some processes on the industrial scale otherwise difficult to solve. An example of this is the possible decomposition of the ammonia solutions of sodium Solvaytechnology by activated magnesia, which in a certain concept allows the production of soda practically without calcium salt waste.

The method described above can be practically applied: 1. Causticization of the material, ie thermal decomposition at such temperatures and times of conversion to effect conversions! 80% magnesium carbonate to the oxide followed by grinding the thermally pretreated material to a 70% below 20 µm specified above. 2. Grinding raw magnesite with simultaneous thermal treatment in mills capable of operating in a stream of burning gases or other heat energy carriers. EXAMPLE 1 Preparation and Reactivation of Active Magnesium Oxide for Modified Solvay Production Technology

The material used was waste magnesite from Jelšava with a 10% raw calcium oxide content. Firing was done in a silite furnace, followed by grinding in a laboratory vibrating mill. Mill power 1.45 kW.kg “^, amplitude 3.5 mm, speed 22.33 with 1 filling 75%. Specification of the samples according to mechanical-thermal activation conditions is in Table 1 / A. The granulometric composition of the samples is shown in Table 2 / A.

Table 1 / A Grinding and firing conditions for individual samples V from orc 1 s Temperature-blowing ° C Milling 1 / A 650 unground 2 / A 650 ground after firing in a vibrating mill 0.25 hrs 3 / Λ 850 unground 4 / A 8 50 ground after firing in a vibrating mill 0.25 hrs 3 210818

Table 2 / A

Granulometric composition of individual samples

Class / <um / Total Percentage Excess for Samples: 1 / A 2 / A 3 / A 4 / A 1 000-500 1 6.80 0.0 14.30 0.0 500-250 45.13 0.0 3 9.43 0.0 250-100 81.58 2.12 71.88 2.08 100-71 89.62 2, 77 83.92 5.41 7 1 -40 93.91 - 9, 23 91.41 15.12 40-20 100.00 28.11 98.50 32.85 20-0 - 100.00 100.00 100.00

Conditions for converting magnesium into solution: The conversion of magnesium into solution was carried out by reaction

MgO + 2 NH 4 Cl = MgCl 2 + 2 NH 3 * H 2 O / 1 / at MgO equivalents: NH 4 Cl = 1.4. The rate of reaction was monitored by determining the amount of ammonia released at one minute intervals.

Fig. 1 shows the kinetics of decomposition of ammonium chloride materials as specified in Table 1 / A. Relevant experimental data are in Table 3 / A. Figure 2 shows the influence of aging on the values of the measured surface and the bound reacted amount of NH 4 Cl, as well as the effect of mechanical reactivation on these quantities.

Table 3 / A Influence of mechanical-thermal activation conditions on the decomposition kinetics of ammonium chloride Distillation time / min / Amount of reacted NH 4 Cl /% / 1 / A 2 / A 3 / A 4 / A 1 15.52 3 3.21 1 4 , 03 23.47 2 28.61 53.51 28.75 44.17 3 39.42 67.31 39, 61 58.32 4 4 7.72 76.40 49.20 68.38 5 5 4.29 8 3.20 56.88 7 6.46 6 5 8.50 88.30 63.06 82.15 7 6 i, 80 9 1.50 65.01 86.54 1 0 69.00 96.70 78, 50 93.67 1 3 73, 90 98.40 84.63 96.42 I 5 76.50 99.10 87.41 97, 29 Meanwhile reacted amount of y 81.00 99.50 92, 00 98,00

Reaction (1) is the master stage of the modified Solvay soda production technology. Clasical Solvay technology uses calcium oxide to regenerate ammonia from the soda lye. The replacement of lime milk by magnesium oxide - and thus the realization of waste-free soda production of refined magnesium oxide - is possible only under the optic conditions of mechanical-magnesium activation. It can be seen from FIG. 1 that sample # 2 makes it possible to realize complete decomposition of ammonium chloride in technologically real time.

Figure 2 demonstrates the adverse effects of aging and thermally and meehanically-thermally prepared active magnesium oxide samples and the favorable reactivation potential of aged materials. Example 2 - Preparation of Active Magnesium Oxide for Modified Sulfate Technology

The material used was magnesite from Jelšava with a 4% calcium oxide content in the raw state.

Mechanical Activation Conditions: The firing was carried out in a rotary kiln at 650 ° C, followed by milling in a commercial lager boron mill. Specimen Specification according to the conditions of preparation of the active magnesium oxide is in Table 1 / B. The granulometric folds of the individual samples are shown in Table 2 / B.

Table 1 / B firing and grinding conditions of individual samples Sample Temperature Grinding firing number ° C 1 / B 650 unground 2 / B 650 milled after ball mill firing 0,25 h 3 / B 650 milled after ball mill firing 0,45 throw

Table 2 / B Granulometric composition of individual samples T rieda / lim / 1 / B Overall percentage of the oversize for samples: 2 / B 3 / B 1 000-500 28,2 0,0 0,0 500-250 60, i 0, 0 0.0 250- 100 9 6.5 14.22,, 25 1 00-60 99.3 5 5.82 3.36 60-40 100.0 8 8, 5 5 8.49 40-20 - 92 , 61 2 2.49 20-0 - 100.00 100.00

Conditions for converting magnesium into solution:

The decomposition of magnesite was carried out by a reaction at the interface of two solid phases: 2 FeSO / j / s / + 2 tlgO / s / + 1.2 02 / g / = 2 MgSO 4 + Fe 2 O 2/2 /

The reaction (2) was run at a ratio of Mg equivalents (): FeSO / (= 1.1 in laboratory electric oven at 5.50 ° C. The heating time was varied between 0.5 and 3 hours. The sample is cooled in an extrudate and stirred at a temperature of 67 DEG to 70 DEG C. The mash is filtered and the magnesium content of the extract is determined in the extract. The reaction time for the samples specified in Table 1 / B is given in Table 3 / B.

Claims

OBJECT OF THE INVENTION

Method of mechanical-thermal activation of magnesium materials for decomposition by weak acids or salts, resp. for decomposition reactions which take place at the interface of two phases, characterized in that the magnesium raw material, e.g. The magnesite, dolomite, is fired at 500 to 800 ° C and ground to 70% below 20 microns at the same time as or after firing.