SU966009A1 - Process for producing magnesium hydrocarbonate - Google Patents

Description

This invention relates to a process for the preparation of magnesium bicarbonate and can be used in the chemical industry.

A method of producing magnesium bicarbonate is known, which includes the action with stirring of aqueous solutions of sodium carbonate with a pH of 9.5-9.8 and the soluble magnesium salt, separating the precipitate of the product, its npoNbiBky and drying.

The closest in technical essence and the achieved result is a method of producing magnesium hydroxyrbonate, including the interaction while mixing aqueous solutions of sodium carbonate and plant. vorimy magnesium salt with preliminary mixing for 10–15 min of a part of the initial reagent with a volume of another reagent, amounted to 4.9–8.45% of an equimolar amount, separating the precipitate of the product, washing and drying

A common disadvantage of the known methods is the duration of the precipitate separation process and the high humidity of the C50 May precipitate. %), which is the reason for the considerable energy consumption for its drying.

The purpose of the invention is to accelerate the separation of sediment and reduce energy consumption for drying by reducing

precipitation moisture. .

This goal is achieved by the fact that according to the method of producing hydrochloric magnesium magnesium, which includes the interaction during the mixing of aqueous sodium carbonate pACTBoipOB

10 and soluble magnesium salt with a preliminary mixing of a part of the source reagent with a volume of another reagent, separation of the product precipitate, washing and drying, preliminarily mixing part of each of the source reagents with the remaining volume of another reagent B: for 2-6 minutes.

It is advisable to preliminary

20, to mix with the remaining volume of the other reagent 2-13% of an equimolar amount of each of. source reagents.

This process leads to the destruction of hydrated shells around the interacting ions, which interfere with the growth of germs and small crystals of magnesium bicarbonate, and the forking of crystals.

Claims (2)

30 products with a more perfect crystal structure, i.e. from mena neva water-holding ability. The method is carried out as follows. The starting reagents (solutions of sodium carbonate and soluble magnesium salt) are fed to separate reactors. At the same time, 2–13% of an equimolar amount of another reactant is continuously fed into each of these reactors. Suspensions separately, stirred for 2-6 minutes, then fed to the reactor, where the suspension is stirred for 315 minutes. Then the suspension is concentrated and bilt. The precipitate is shed and sustained. With the pre-mixing time of the slurry over a given interval of {2-6 minutes, the rate of sedimentation and its moisture content are at the level of the known method. Example 1. Take 330 ml of HgSO solution. concentration of 220 g / l and 426 ml of Na solution. concentration of 150 g / l. The temperature of the solutions. From the indicated quantities of reagent tone, 23 ml of MgSO solution are taken. and 27 ML of the Na.CO solution, 23 ml of the solution of MD SO are added, with stirring, to 399 ml of the solution. NajjCg, which is 7% of an equimolar quantity, and 27 ml of the second solution is poured in T to 307 ml of an MD50 solution, which is 6% of the equimolar amount. The two dry mixes formed are mixed for 3 min and fed in equimolar proportions along a common inclined chute into the reactor, where they are stirred for 6 min. Next, the suspension is concentrated in the sump and filtered. Filtration rate at 300 mm vacuum. Hg Art. 4-hv h. The precipitate is washed, dried, receive 66.3. g trihydrocarbonate magnesium, which corresponds to 19.3 g MDO. Water flow rate is .0.48 l, i.e. 7.2 tons) 0 or 25 m Vi MgO. Humidity sediment 41 wt.%. Example 2. 770 ml of MgCl 2 races are taken, with a concentration of ,, 260 g / l and 1590 ml of N32.00 solution. Concentration 140 g / l. Solution temperature 25С. 150 ml of solution are recovered. and 90 MP MgClj solution. and poured, with stirring, to 680 ml of MgClI solution and to 1440 ml of solution, respectively. The amount of reagents added is respectively 10.7 and 13 molar percent. The suspension of magnesium trihydrocarbonate, containing an excess of Naj, CO, is stirred for 6 min, and the cTien3} tK), containing an excess of MgCl. 2 minutes. Further, as in Example 1, the suspensions are fed to a common intermediate reactor with a residence time of 3 minutes, and then to the reactor, where the suspension is also stirred for 3 minutes. Next, the suspension is concentrated in the sump and the condensed part is filtered. Filtration rate at 300 mm Hg vacuum. Art. 4.3 h After sizing and drying the precipitate, 238.4 g of magnesium trihydrocarbonate is obtained, which corresponds to 69.5 g of MgO. Wash water consumption 1.9 l, i.e. 8.0 m per ton of MgCO.j. or 27., 4 MVT MDO. Sediment humidity 42.6 May. % Example 3. Under the initial conditions of Example 1, 10 ml of magnesium sulfate solution and 9.6 ml of sodium carbonate solution were isolated and poured with stirring to 416.4 ml of sodium carbonate solution and 320 ml of magnesium sulfate, respectively. Meanwhile, the amount of reagents added to the solutions of magnesium sulfate and sodium carbonate is 2 and 3.1% molar, respectively. Both suspensions are {stirred for 6 minutes, served in the same manner as in Example 1, into a common intermediate reactor with jipeMeHeM stay in it for 0.3 minutes, and then into the reactor, where it is stirred for 15 minutes. Next, the suspension is concentrated in the sump and the condensed part is filtered. Filtration rate at 300 mm Hg vacuum. Art. 4.4 mb / m-. Part of the product corresponds to example 1. The consumption of wash water is 0.49 l, i.e. 7.4 m per 1 ton. 0 or 25.4 m VT MgO. Sediment humidity 40.8 May. % According to a known method under the conditions of examples 1-3, a product is obtained with a moisture content of 51.6-56.8%, o. filtering suspension 1.8-2.3 m / m-h. The technical and economic advantages of the proposed method consist in increasing the filtration rate of the suspension by 2.2 times and reducing the moisture content of the product sediment by 7-16%, which reduces the energy consumption for drying the sediment to 235 kg of equivalent fuel per ton of MDO versus 320 kg / t MDO, by a known method. Claim 1. Method for producing magnesium bicarbonate, including reacting with stirring aqueous solutions of sodium carbonate and soluble magnesium salt with preliminary mixing of a portion of the starting reagent with the volume of another reagent, separating the product, its washing and drying, characterized in that separating the sludge and reducing the energy consumption for drying by reducing the moisture content of the sludge, pre-mix part of the kg of each of the initial reagents 5966009 6 This is with the remaining volume of other sources of information, reagent for 2 min. minutes taken into account during the examination 2. The method of pop4D, is also distinguished by the fact that the preliminary- 1. USSR author's certificate the mixture is mixed with the remaining volume of 277752, cl. C 01 F 5/24, 1967. another reagent is subjected to 2-13% 2. USSR copyright certificate an equimolar amount of each of 623827, cl. C 01 F 5 / 02,1973 (occurring reagents. Type).