CN113008726A - Device and method for determining components of ammonium carnallite dehydrated material - Google Patents

Abstract

The invention relates to a device and a method for measuring the composition of ammonium carnallite dewatering material. The device includes a reactor, a gas escape hole, a gas outlet pipe, a primary deceleration separator, a separator connecting pipe, a secondary deceleration separator, a separation medium and an absorption device. The method includes the following steps: (a) accurately weighing the potassium chloride, sodium chloride and ammonium carnallite dehydrated materials, and then distributing them in the reactor; (b) heating the above materials to keep the measuring device in the correct position. Pressing, separating and recovering ammonium chloride and ammonia; (c) accurately weighing the recovered ammonium chloride, ammonia and the materials in the reactor after the reaction, and determining the composition of the ammonium carnallite dehydrated material by calculation. The invention avoids the problems of uneven sampling and mutual influence of various components caused by traditional testing methods, and can realize simultaneous and accurate determination of different components of the ammonium carnallite dewatering material.

Description

A kind of measuring device and method of ammonium carnallite dewatering material composition

technical field

The invention relates to a method and a device for measuring the composition of a dewatering material, in particular to a device and a method for measuring the composition of an ammonium carnallite dewatering material.

Background technique

A large amount of biscuit (MgCl ₂ ·6H ₂ O) is discharged during the comprehensive utilization of Qinghai Salt Lake and the process of seawater desalination in China, and its massive discharge and accumulation have seriously affected the local ecological environment. The preparation of magnesium metal by dehydration-electrolysis process using bischofite as raw material is an important way to realize the sustainable development of magnesium resources in my country. For example, the preparation of metal magnesium in the metal magnesium integration project of Qinghai Salt Lake Group in my country is to use the rich bischofite in the salt lake as the raw material. First, dehydration is carried out in a hot air fluidized dryer (the air temperature in this section of the dryer is 361 ℃), and then continue dehydration in the hydrogen chloride fluidized bed dryer (the air temperature in this section of the dryer is 365℃) to prepare anhydrous magnesium chloride with higher purity, and then prepare metal magnesium through electrolysis. In order to reduce the hydrolysis of bischite during heating and dehydration to improve the electrolysis process, some researchers first synthesized ammonium carnallite (NH ₄ Cl·MgCl ₂ ·6H ₂ O) using bisquecite as raw material, and then dehydrated - Electrolysis link. For example, the Qinghai Salt Lake Institute of the Chinese Academy of Sciences conducted a scale-up experiment on the preparation of ammonium carnallite and its fluidized dehydration around 1980. They first dehydrated the ammonium carnallite in two stages (the bed temperature was 160 °C and 310 °C) to prepare its dehydrated material, and then electrolyzed to obtain metallic magnesium.

It can be seen that bischofite dehydrated material and ammonium carnallite dehydrated material are important raw materials for electrolytic preparation of magnesium metal, and their components have a great influence on the subsequent electrolysis process, so it is very important to accurately determine their components. The determination of the composition of the ammonium carnallite dewatering material is mainly to accurately determine the contents of MgCl ₂ , H ₂ O, NH ₄ Cl and MgOHCl. The method for determining the composition of ammonium carnallite dewatering material is mainly the "individual determination method of each component" proposed by the Qinghai Salt Lake Institute of the Chinese Academy of Sciences in the 1980s. The specific implementation process is as follows:

1. Determination of MgOHCl content

Take two samples, one to measure acid-soluble magnesium and the other to measure water-soluble magnesium, the difference is the insoluble magnesium, and then the insoluble magnesium is converted into the content of MgOHCl in the sample. However, our study found (for details: Zhimin Zhang etl., The conversion from magnesium hydroxychloride to anhydrous magnesium chloride by solid-state reaction. Metallurgical and Materials Transactions B, 47B (2016), 773-778) that MgOHCl dissolved in water would Part of MgCl ₂ is formed, and the conversion amount varies with the amount of water and the height of temperature. Therefore, inferring the content of MgOHCl by measuring the water-insoluble magnesium will inevitably bring great errors.

_2. Determination of MgCl content

Accurately weigh about 0.1 g of the sample and place it in a dry, 50 mL ground-mouth conical flask with electromagnetic stirring. 25 mL of absolute ethanol was added, stirred for 1 hour and left to clarify, and then 5 mL of the supernatant was taken for measurement. The magnesium ion and chloride ion were titrated with EDTA and Hg(NO ₃ ) ₂ respectively, and then the content of MgCl ₂ was calculated. Since the dehydrated material contains a certain amount of crystal water, after the crystal water dissolves into ethanol, the effect on the titration process is as follows: (1) MgOHCl in the material directly reacts with H ₂ O to generate MgCl ₂ (see literature for details: Xia Shuping, Sun Yufen, Alkali Preparation of magnesium chloride and research on its physical and chemical properties (1).); (2) In the presence of crystal water, MgOHCl and NH ₄ Cl react to form MgCl ₂ . It can be seen that there is a large error in determining the content of magnesium chloride by measuring magnesium ions and chloride ions in ethanol.

3. Determination of H ₂ O content

The content of crystal water in the dehydrated material was determined by Karl Fischer reagent titration. However, this method is not suitable for the determination of crystallization water content in the dehydrated materials of bischofite and ammonium carnallite from the mechanism. During the heating process, bismuthite and ammonium carnallite generate hydrolyzed product MgOHCl, which easily reacts with Karl Fischer reagent, resulting in a seriously high experimental result. In addition, there are also literatures that propose dehydration by heating and accurate determination of water quality. However, during the heating process, part of the crystal water undergoes hydrolysis reaction with magnesium chloride to generate a hydrolyzed product MgOHCl, resulting in the escape of water and cannot truly reflect the crystal water content in the material.

Accurate determination of the composition of ammonium carnallite dehydration material is the premise of formulating and optimizing the dehydration process, and it is also the key link to improve the current efficiency and reduce the energy consumption of electrolysis in the process of electrolytic preparation of magnesium metal. At present, the key problems affecting the accurate determination of the composition of ammonium carnallite dewatering material are: (1) The individual measurement of each component leads to uneven sampling, and the measurement results of each component do not match, which cannot truly reflect the composition of the dewatering material. The particle size of ammonium carnallite dewatering material is distributed between 0.05mm and 5.00mm, and the composition of different particle size dewatering materials is very different. The individual measurement of each component can easily cause the sample to fail to reflect the true particle size distribution of the material, and the particle size distribution of each sampling varies greatly, resulting in mismatched and inaccurate test results for each component; large, resulting in a very large error in the test results. H ₂ O and NH ₄ Cl have a great influence on the determination of MgCl ₂ and MgOHCl content. No matter in aqueous medium or organic medium, H ₂ O and NH ₄ Cl in the material can react with MgOHCl to form MgCl ₂ respectively, resulting in MgCl ₂ and MgOHCl. The measurement error of MgOHCl content is very large; (3) The crystal water in the dehydrated material can easily react with the component MgCl ₂ during the heating and removal process, so the quantitative analysis of H ₂ O in the material cannot be performed by simply heating and removing.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a measuring device and method for the composition of ammonium carnallite dewatering material in view of the deficiencies of the prior art, so as to simultaneously and accurately measure different components of the ammonium carnallite dewatering material.

In order to solve the above-mentioned technical problems, the content of the present invention includes:

A measuring device for the composition of ammonium carnallite dehydration material, the measuring device comprises a reactor, a primary deceleration separator, a secondary deceleration separator, an absorption device and a heating furnace; the reactor is arranged in the heating furnace, and The top of the reactor is provided with a gas escape hole, the gas escape hole is communicated with the top of the first-stage deceleration separator through a gas outlet pipe, and one side of the first-stage deceleration separator is connected to the second stage through the separator connecting pipe. One side of the secondary deceleration separator is communicated, and the top of the secondary deceleration separator is communicated with the absorption device through a second gas outlet pipe, and a separation medium is arranged in the second gas outlet pipe.

Further, the ratio of the diameter of the gas escape hole to the diameter of the reactor is 0.01-0.5.

Further, the ratio of the diameter of the primary deceleration separator and the secondary deceleration separator to the diameter of the gas outlet pipe is 2.5-55.0.

A method for utilizing the above-mentioned measuring device to measure the composition of ammonium carnallite dewatering material, comprising the steps of:

(a) Weighing and batching the potassium chloride, sodium chloride and ammonium carnallite dehydrated materials, and then distributing them in the reactor;

(b) heating the above-mentioned materials while maintaining the positive pressure in the measuring device, and then separating and recovering the ammonium chloride and ammonia gas that escaped during the reaction;

(c) Weigh the recovered ammonium chloride, ammonia gas and the materials in the reactor after the reaction, and calculate and determine the composition of the ammonium carnallite dehydration material.

Further, in the step (a), the feeding amount of the ammonium carnallite dehydrating material is 1.00 parts by weight, the feeding amount of potassium chloride is 0.20-5.50 parts by weight, and the feeding amount of sodium chloride is 0.10-4.50 parts by weight parts by weight.

Further, in the step (a), the molecular formula of the ammonium carnallite dehydration material is expressed as n NH ₄ Cl · MgCl ₂ · m H ₂ O, wherein, 1.5> n ≥ 0.2, 4.5 ≥ m >0, the hydrolysis product The content of MgOHCl is 0.01wt.%~30wt.%.

Further, in the step (a), cloth is carried out in the reactor according to one of the following two methods: the potassium chloride and sodium chloride are mixed and spread on the bottom, and the ammonium carnallite dewatering material is spread on the top; Completely mix potassium chloride, sodium chloride and ammonium carnallite dewatering material; ensure that the ratio of material height to its diameter is 0.02~8.5.

Further, in the step (b), the heating method of the material is as follows: firstly, the temperature is kept at 290-380°C for 0.1-3.5 hours, and then the temperature is kept at 380-600°C for 0.05-5.0 hours; meanwhile, the gas pressure inside the device is maintained during the heating process. It is ﹢0.001~﹢0.05 standard atmospheric pressure.

Further, in the step (c), the ammonium chloride escaping during the reaction is recovered in a solid form, and the ammonia gas escaping during the reaction is absorbed in a gaseous state.

Further, in the step (c), the formula for calculating the composition of the ammonium carnallite dewatering material is: the magnesium chloride content is: [ m ₁ + m ₂ - m ₅ -( m ₄ /17)*95]/ m ₂ ; The content of ammonium chloride is: [ m ₃ +( m ₄ /17)*53.5]/ m ₂ ; the content of magnesium hydroxychloride is: ( m ₄ /17)*76.5/ m ₂ ; the content of water is: [ m ₁ + m ₂ - m ₃ - m ₄ - m ₅ -( m ₄ /17)*18]/ m ₂ ; where m ₁ is the mass sum of potassium chloride and sodium chloride, m ₂ is the mass of ammonium carnallite dehydration material, m3 is the mass _of the _ammonium chloride collected after the reaction, m4 is the mass of the ammonia gas absorbed after the reaction, and m5 is the _mass of the material in the reactor after the reaction.

The beneficial effects of the present invention are:

(1) Comprehensive determination of each component, and the test results of each component match. The components in the ammonium carnallite dewatering material are simultaneously measured in a set of measuring devices, which avoids the problem of mismatching test results of each component caused by multiple sampling tests; (2) By increasing the ammonium carnallite The quality of stone sampling and repeated tests can effectively reduce the errors caused by uneven sampling of materials. This test method does not use the titration method to determine the content of each component, so the sampling amount of ammonium carnallite can be increased, and the problem of poor sampling uniformity caused by small sampling amount is greatly reduced; It avoids the interaction between the components caused by the analysis of water or organic systems; (4) By effectively controlling the distribution method, heating method and gas escape method, the crystal water in the material is completely removed (no hydrolysis occurs) And the complete conversion of MgOHCl, greatly improving the test accuracy.

Description of drawings

Fig. 2 is the device schematic diagram of the present invention measuring the composition of ammonium carnallite dewatering material;

Fig. 1 is the flow chart that the present invention measures the composition of ammonium carnallite dewatering material;

In the figure: 1-reactor, 2-first stage deceleration separator, 3-second stage deceleration separator, 4-separation medium, 5-absorption device, 6-heating furnace, 7-gas escape hole, 8-gas outlet tube, 9-separator connection tube.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

As shown in Figure 1, the present invention provides a device for measuring the composition of ammonium carnallite dehydration material, the measuring device includes a reactor 1, a primary deceleration separator 2, a secondary deceleration separator 3, an absorption device 5 and a heating Furnace 6; Reactor 1 is arranged in the heating furnace 6, and the top of the reactor 1 is provided with a gas escape hole 7, and the gas escape hole 7 is communicated with the top of the first-stage deceleration separator 2 through a gas outlet pipe 8, One side of the primary deceleration separator 2 is communicated with one side of the secondary deceleration separator 3 through the separator connecting pipe 9, and the top of the secondary deceleration separator 3 is communicated with the absorption device 5 through the second gas outlet pipe 8 , the second gas outlet pipe 8 is provided with a separation medium 4 .

The material is fed into the reactor 1 according to a certain distribution method, and the material is heated by the heating furnace 6 . The gas escaping during the heating process escapes from the gas escape hole 7, passes through the gas outlet pipe 8 and then enters the primary deceleration separator 2, the separator connecting pipe 9 and the secondary deceleration separator 3 in turn, thereby realizing ammonia and The mixing of hydrogen chloride gas, the precipitation of ammonium chloride and the primary separation of ammonia and ammonium chloride produced by the conversion of MgOHCl; and then the secondary separation of ammonia and ammonium chloride produced by the conversion of MgOHCl is carried out by using separation medium 4, thereby realizing ammonium chloride. Accurate determination of each component of carnallite dewatering material.

The ratio of the diameter of the gas escape hole 7 to the diameter of the reactor 1 is 0.01-0.5. Preferably, the ratio of the diameter of the gas escape hole 7 to the diameter of the reactor 1 is 0.05~0.4; further preferably, the ratio of the diameter of the gas escape hole 7 to the diameter of the reactor 1 is 0.08~0.3. When the ratio of the diameter of the reactor 1 to the diameter of the gas escape hole 7 is within a certain range, it can play the following roles: (1) Effectively suppress the escape rate of ammonium chloride in the dehydrated material, so that it can be completely mixed with MgOHCl. (2) The ammonia gas and hydrogen chloride gas released by the decomposition of ammonium chloride are initially mixed to avoid the separation of the two gases caused by the difference in the diffusion rate.

The ratio of the diameter of the primary deceleration separator 2 and the secondary deceleration separator 3 to the diameter of the gas outlet pipe 8 is 2.5 to 55.0. Preferably, the ratio of the diameter of the primary deceleration separator 2 and the secondary deceleration separator 3 to the diameter of the gas outlet pipe 8 is 5.0-50.0; further preferably, the diameter of the primary deceleration separator 2 and the secondary deceleration separator 3 The ratio of the diameter to the diameter of the gas outlet pipe 8 is 8.0 to 45.0. By defining the ratio of the diameter of the primary deceleration separator 2 or the secondary deceleration separator 3 to the gas outlet pipe 8, the complete mixing of hydrogen chloride and ammonia gas and the complete sedimentation of ammonium chloride can be achieved, which greatly improves the MgOHCl and _NH4 Accuracy of Cl content determination.

As shown in Figure 2, the method of the present invention measures the flow chart of the ammonium carnallite dewatering material composition, and the specific measurement process is:

(a) Accurately weighing and batching potassium chloride, sodium chloride and ammonium carnallite dewatering material, the feeding amount of ammonium carnallite dewatering material is 1.00 parts by weight, and the feeding amount of potassium chloride is 0.20~5.50 Parts by weight, the feeding amount of sodium chloride is 0.10 ~ 4.50 weight parts; Preferably, the feeding amount of ammonium carnallite dehydration material is 1.00 weight parts, the feeding amount of potassium chloride is 0.30 ~ 5.00 weight parts, chloride The feeding amount of sodium is 0.20 ~ 4.00 parts by weight; further preferably, the feeding amount of the ammonium carnallite dehydration material is 1.00 weight parts, the feeding amount of potassium chloride is 0.50 ~ 4.50 weight parts, the feeding amount of sodium chloride It is 0.40 to 3.00 parts by weight. The molecular formula of ammonium carnallite dehydration material is expressed as n NH ₄ Cl · MgCl ₂ · m H ₂ O, wherein, 1.5 > n ≥ 0.2, 4.5 > m > 0, and the content of hydrolyzed product MgOHCl is 0.01wt.%~30wt.% Then carry out cloth in reactor 1 according to one of the following two ways: after potassium chloride and sodium chloride are mixed, spread on the bottom, ammonium carnallite dewatering material is spread on the top, or potassium chloride, chloride The sodium and ammonium carnallite dewatering materials are completely mixed; ensure that the ratio of the height of the material to its diameter is 0.02 to 8.5; preferably, the ratio of the height of the material to its diameter is 0.05 to 8.0; more preferably, the ratio of the height of the material to its diameter is 0.1 to 7.0 .

(b) using the heating furnace 6 to heat the above-mentioned materials in the reactor 1, firstly at 290-380°C for 0.1-3.5 hours, and then at 380-600°C for 0.05-5.0 hours; preferably, firstly at 300-370°C ℃ of insulation for 0.3-3.0 hours, then at 390-580 ℃ for 0.2-4.0 hours; further preferably, firstly at 310-350 ℃ for 0.5-2.5 hours, then at 400-550 ℃ for 0.3-3.5 hours; keep heating at the same time In the process, the gas pressure inside the measuring device is +0.001～+0.05 standard atmospheric pressure; preferably, the gas pressure inside the device during the heating process is ﹢0.002～﹢0.04 standard atmospheric pressure; further preferably, the gas pressure inside the device during the heating process is ﹢ 0.003~﹢0.03 standard atmospheric pressure; then the ammonium chloride escaped in the reaction process is recovered in solid form, and the ammonia gas escaped in the reaction process is absorbed in gaseous state.

(c) After the product is cooled, the recovered ammonium chloride, ammonia gas and the materials in the reactor after the reaction are weighed, and the composition of the ammonium carnallite dehydrated material is calculated and determined.

The formula for calculating the composition of ammonium carnallite dewatering material is: the content of magnesium chloride is: [ m ₁ + m ₂ - m ₅ - ( m ₄ /17)*95]/ m ₂ ; the content of ammonium chloride is: [ m ₃ + ( m 4/17 _{)*53.5]/m 2 ; the magnesium hydroxychloride content is: ( m 4} /17)*76.5/ _m 2 _; the _water content is: [ m ₁ + m ₂ - m ₃ - m ₄ - m ₅ - ( m 4/17)* ₁₈ ]/ m ₂ ; where m ₁ is the mass sum of potassium chloride and sodium chloride, m ₂ is the mass of ammonium carnallite dehydration material, and m ₃ is the ammonium chloride collected after the reaction m ₄ is the mass of ammonia gas absorbed after the reaction, m ₅ is the mass of the material in the reactor after the reaction.

The testing mechanism of the present invention is as follows: when potassium chloride, sodium chloride and ammonium carnallite dehydration material are heated under certain conditions, all MgOHCl in the ammonium carnallite dehydration material undergoes chemical reaction with NH ₄ Cl therein to generate a product Three products _MgCl2 , _NH3 and _H2O . Through the absorption and quantitative analysis of gaseous ammonia, the content of MgOHCl in the dehydrated material can be reversely obtained; on this basis, the dehydrated ammonium carnallite dehydration can be obtained by collecting the solid NH ₄ Cl escaping during the reaction and accurately weighing it. The content of NH ₄ Cl in the material; the solid product in the reactor after the reaction is NaCl- _KCl -MgCl ternary molten salt, combined with the amount of potassium chloride and sodium _chloride and the amount of MgCl obtained from the conversion of MgOHCl in the material, can be Infer the content of MgCl ₂ in the dehydrated material; according to the weight loss of the materials before and after the reactor, combined with the content of NH ₄ Cl and MgOHCl in the dehydrated material, the content of H ₂ O in the dehydrated material can be inferred.

In step (a), the effect of the distribution method and the material height-diameter ratio on the component test is as follows: (1) NH ₄ Cl in the dehydrated material can chemically react with another component of MgOHCl in the dehydrated material during the heating process. By rationally distributing the material and controlling the ratio of the height to the diameter of the material within a certain range, the decomposition and escape rate of NH ₄ Cl in the material can be reduced so that it can completely react with MgOHCl, which ensures the accuracy of the test; (2) NH ₄ Cl high temperature analysis It is explained that NH ₃ and HCl gas are released, and there are differences in the escape rates of the two in the material and in the gaseous environment, which will greatly affect the accurate determination of NH ₃ . By rationally distributing the material and controlling the ratio of the height to the diameter of the material within a certain range, the relative diffusion distance of the two gases in the material can be reduced, thereby avoiding its influence on the determination of NH ₃ .

In step (b), the heating method has the following effects on the component test: (1) The first stage of segmented heating can make most of the H ₂ O removed in the first stage, and avoid a large amount of water vapor escaping and affecting the composition. Unbalanced dissolution of _NH3 and HCl, and effectively avoids hydrolysis during the heating process of the material, which greatly improves the accuracy of the test; (2) The second stage of segmented heating can make the final product in the reactor in the form of molten salt. , NH ₄ Cl is basically insoluble in the NaCl-KCl-MgCl ₂ ternary molten salt system, so as to ensure the accuracy of NH ₄ Cl content determination; (3) Staged heating can make NH ₃ escape and NH 3 obtained from MgOHCl conversion ₄ The NH ₃ generated by the decomposition of Cl is separated in time to avoid mutual influence between the two; (4) the molten salt is basically non-volatile during the heating process, and does not affect the test results.

In step (b), the gas pressure inside the device during the heating process is limited to +0.001~+0.05 standard atmospheric pressure, so that NH ₃ and HCl released by the decomposition of NH ₄ Cl can be fully mixed and recombined into solid NH ₄ at low temperature. Cl, thus avoiding its influence on the MgOHCl content test and greatly improving the accuracy of the NH ₄ Cl content test.

The products prepared according to the present invention were tested according to the following methods.

The mass sum ( m ₁ ) of potassium chloride and sodium chloride and the mass of ammonium carnallite dehydrated material ( m ₂ ) were determined by weighing with a precision electronic balance (reading accuracy of at least 0.0001g). After the completion of the reaction, the solid ammonium chloride was collected and weighed ( m ₃ ), and the material in the reactor after the reaction was collected and weighed ( m ₅ ). The ammonia-absorbing medium was collected and weighed ( m ₄ ). Then, utilize the following formula to calculate the composition of ammonium carnallite dewatering material:

Wherein, the magnesium chloride content is: [ m ₁ + m ₂ - m ₅ - ( m ₄ /17)*95]/ m ₂ ;

Ammonium chloride content is: [ m ₃ + ( m ₄ /17)*53.5]/m ₂ ;

The content of magnesium hydroxychloride is: ( m ₄ /17)*76.5/m ₂ ;

The water content is: [ m1 ₊ m2 _- m3 _- m4 _- m5- ₍ m4 / ₁₇ )* ₁₈ ]/ m2

Typical but non-limiting examples of the present invention are as follows:

Example 1

Weigh 100.0001g potassium chloride, 150.0005g sodium chloride and 100.0003 ammonium carnallite dehydrated material with an electronic balance (the composition of the dehydrated material measured by ICP, ion chromatography and EDTA titration is _1.2NH4Cl · _MgCl2 · 1.1H ₂ O, the hydrolyzate MgOHCl content is 0.89wt.%) for mixing. The above mixture was placed in a reactor to ensure a material height to diameter ratio of 4.3. The material was kept at 330°C for 3.0 hours, then at 450°C for 3.5 hours, and the gas pressure inside the reactor was kept at 0.01 standard atmosphere during heating. After the reaction is completed, the solid ammonium chloride, the materials in the reactor and the medium for absorbing ammonia gas are collected and weighed.

The composition of ammonium carnallite obtained by calculation is 1.1NH ₄ Cl·MgCl ₂ ·1.1H ₂ O, and the content of MgOHCl of the hydrolysis product is 0.87wt.%.

Example 2

Weigh 20.0004g of potassium chloride and 10.0006g of sodium chloride with an electronic balance and mix, and spread the mixture on the bottom of the reactor; weigh 99.9994g of ammonium carnallite dehydrated material (using ICP, ion chromatography and EDTA titration comprehensively) The composition of the dehydrated material obtained by the method is 0.2NH ₄ Cl·MgCl ₂ , and the content of the hydrolyzed product MgOHCl is 30wt.%), and the ammonium carnallite dehydrated material is spread on the upper part to ensure that the ratio of material height to diameter is 8.5. The material was kept at 290°C for 0.1 hour, then at 380°C for 0.05 hour, and the gas pressure inside the reactor was kept at 0.05 standard atmosphere during the heating. After the reaction is completed, the solid ammonium chloride, the materials in the reactor and the medium for absorbing ammonia gas are collected and weighed.

The composition of ammonium carnallite obtained by calculation is 0.2NH ₄ Cl·MgCl ₂ ·0.01H ₂ O, and the content of hydrolyzed product MgOHCl is 29.9wt.%.

Example 3

Weigh 549.9998g of potassium chloride and 450.0002g of sodium chloride with an electronic balance and mix, and spread the mixture on the bottom of the reactor; weigh 99.9998g of ammonium carnallite dehydrated material (using ICP, ion chromatography and EDTA titration comprehensively) The composition of the dehydrated material determined by the method is 1.5NH ₄ Cl·MgCl ₂ ·4.5H ₂ O, and the content of the hydrolyzed product MgOHCl is 0.01wt.%), and the ammonium carnallite dehydrated material is spread on the upper part to ensure the ratio of material height to diameter is 6.0. The material was kept at 380°C for 3.5 hours, then at 600°C for 5.0 hours, and the gas pressure inside the reactor was kept at 0.001 standard atmosphere during the heating process. After the reaction is completed, the solid ammonium chloride, the materials in the reactor and the medium for absorbing ammonia gas are collected and weighed.

The composition of ammonium carnallite obtained by calculation is 1.5NH ₄ Cl·MgCl ₂ ·4.4H ₂ O, and the content of hydrolyzed product MgOHCl is 0.01wt.%.

Example 4

Weigh 300.0007g potassium chloride, 300.0001g sodium chloride and 100.0003 ammonium carnallite dehydrated material with an electronic balance (the composition of the dehydrated material measured by ICP, ion chromatography and EDTA titration is _0.7NH4Cl · _MgCl2 · 2.2H ₂ O, the hydrolyzate MgOHCl content is 15.3 wt.%) for mixing. The above mixture was placed in a reactor to ensure a material height to diameter ratio of 0.02. The material was kept at 350°C for 1.0 hour, then at 550°C for 0.5 hour, and the gas pressure inside the reactor was kept at 0.008 standard atmosphere during the heating. After the reaction is completed, the solid ammonium chloride, the materials in the reactor and the medium for absorbing ammonia gas are collected and weighed.

The calculated composition of ammonium carnallite is 0.7NH ₄ Cl·MgCl ₂ ·2.2H ₂ O, and the content of hydrolyzed product MgOHCl is 15.4wt.%.

Example 5

Weigh 399.9996g potassium chloride, 400.0003g sodium chloride and 100.0000 ammonium carnallite dehydrated material with an electronic balance (the composition of the dehydrated material measured by ICP, ion chromatography and EDTA titration is _1.4NH4Cl · _MgCl2 · 0.8H ₂ O, the hydrolyzate MgOHCl content is 5.8wt.%) for mixing. The above mixture was placed in a reactor to ensure a material height to diameter ratio of 3.5. The material was kept at 380°C for 2.0 hours, then at 500°C for 1.0 hours, and the gas pressure inside the reactor was maintained at 0.03 standard atmosphere during heating. After the reaction is completed, the solid ammonium chloride, the materials in the reactor and the medium for absorbing ammonia gas are collected and weighed.

The composition of ammonium carnallite obtained by calculation is 1.3NH ₄ Cl·MgCl ₂ ·0.9H ₂ O, and the content of hydrolyzed product MgOHCl is 5.7wt.%.

Example 6

Weigh 500.0004g potassium chloride, 300.0002g sodium chloride and 99.9995 ammonium carnallite dehydrated material with an electronic balance (the composition of the dehydrated material obtained by comprehensively using ICP, ion chromatography and EDTA titration method is _2.1NH4Cl · _MgCl2 · 1.4H ₂ O, the hydrolyzate MgOHCl content is 3.4wt.%) for mixing. The above mixture was placed in a reactor to ensure a material height to diameter ratio of 4.5. The material was kept at 290°C for 3.5 hours, then at 550°C for 0.5 hours, and the gas pressure inside the reactor was kept at 0.02 standard atmosphere during heating. After the reaction is completed, the solid ammonium chloride, the materials in the reactor and the medium for absorbing ammonia gas are collected and weighed.

The calculated composition of ammonium carnallite is 2.1NH ₄ Cl·MgCl ₂ ·1.3H ₂ O, and the content of hydrolyzed product MgOHCl is 3.3wt.%.

Example 7

Weigh 320.0002g potassium chloride, 380.0005g sodium chloride and 100.0004 ammonium carnallite dehydrated material with an electronic balance (the composition of the dehydrated material measured by ICP, ion chromatography and EDTA titration is _0.9NH4Cl · _MgCl2 · 0.5H ₂ O, the hydrolyzate MgOHCl content is 1.3wt.%) for mixing. The above mixture was placed in a reactor to ensure a material height to diameter ratio of 3.1. The material was kept at 330°C for 1.5 hours, then at 480°C for 2.5 hours, and the gas pressure inside the reactor was maintained at 0.009 standard atmosphere during heating. After the reaction is completed, the solid ammonium chloride, the materials in the reactor and the medium for absorbing ammonia gas are collected and weighed.

The calculated composition of ammonium carnallite is 0.8NH ₄ Cl·MgCl ₂ ·0.4H ₂ O, and the content of hydrolyzed product MgOHCl is 1.2wt.%.

Although the present invention illustrates the detailed process parameters and process flow of the present invention through the above-mentioned embodiments, the present invention is not limited to the above-mentioned detailed process parameters and process flow, that is, it does not mean that the present invention must rely on the above-mentioned detailed process parameters and process flow. implement. Those skilled in the art should understand that any improvement of the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims (10)

1. A measuring device for the composition of ammonium carnallite dewatering material, characterized in that: the measuring device comprises a reactor (1), a primary deceleration separator (2), a secondary deceleration separator (3), an absorption device (5) and a heating furnace (6); the reactor (1) is arranged in the heating furnace (6), and the top of the reactor (1) is provided with a gas escape hole (7), the gas escape hole (7) A gas outlet pipe (8) is communicated with the top of the primary deceleration separator (2), and one side of the primary deceleration separator (2) is connected to the secondary deceleration separator through the separator connecting pipe (9). One side of the separator (3) is communicated, and the top of the secondary deceleration separator (3) is communicated with the absorption device (5) through a second gas outlet pipe (8), the second gas outlet pipe A separation medium (4) is provided in (8). 2 . The device for measuring the composition of ammonium carnallite dehydrating material according to claim 1 , wherein the ratio of the diameter of the gas escape hole ( 7 ) to the diameter of the reactor ( 1 ) is 0.01 to 0.5. 3 . 3. The device for measuring the composition of ammonium carnallite dehydration material according to claim 1, characterized in that: the diameters of the first-stage deceleration separator (2) and the second-stage deceleration separator (3) are related to the diameter of the gas outlet pipe (8). ) diameter ratio is 2.5~55.0. 4. a method utilizing the measuring device described in any one of claims 1 to 3 to measure the composition of ammonium carnallite dewatering material, is characterized in that: described method comprises the steps: (a) Weighing and batching the potassium chloride, sodium chloride and ammonium carnallite dehydrated materials, and then distributing them in the reactor; (b) heating the above-mentioned materials while maintaining the positive pressure in the measuring device, and then separating and recovering the ammonium chloride and ammonia gas that escaped during the reaction; (c) Weigh the recovered ammonium chloride, ammonia gas and the materials in the reactor after the reaction, and calculate and determine the composition of the ammonium carnallite dehydration material. 5. The method for determining the composition of ammonium carnallite dewatering material according to claim 4, characterized in that: in the step (a), the amount of ammonium carnallite dewatering material to be fed is 1.00 parts by weight, and potassium chloride The feeding amount of sodium chloride is 0.20~5.50 parts by weight, and the feeding amount of sodium chloride is 0.10~4.50 parts by weight. 6. The method for determining the composition of ammonium carnallite dewatering material according to claim 4, characterized in that: in the step (a), the molecular formula of the ammonium carnallite dewatering material is expressed as n NH ₄ Cl·MgCl ₂ · m H ₂ O, wherein, 1.5> n ≥ 0.2, 4.5 ≥ m > 0, and the content of the hydrolyzed product MgOHCl is 0.01wt.%~30wt.%. 7. The method for determining the composition of ammonium carnallite dewatering material according to claim 4, in the step (a), cloth is carried out in the reactor (1) according to one of the following two methods: potassium chloride and chlorine After mixing the sodium chloride, spread it on the bottom, and spread the ammonium carnallite dewatering material on the upper part; mix the potassium chloride, sodium chloride and ammonium carnallite dewatering material completely; ensure that the ratio of the height of the material to its diameter is 0.02~8.5. 8. The method for determining the composition of ammonium carnallite dewatering material according to claim 5, in the step (b), the heating method of the material is: firstly, the temperature is kept at 290-380°C for 0.1-3.5 hours, and then at 380-600°C. ℃ for 0.05~5.0 hours; at the same time, keep the gas pressure inside the device at ﹢0.001~﹢0.05 standard atmospheric pressure during the heating process. 9. The method for determining the composition of ammonium carnallite dewatering material according to claim 5, in the step (c), the ammonium chloride escaped in the reaction process is recovered in solid form, and the ammonium chloride escaped in the reaction process is recovered in a solid state. Ammonia gas undergoes gaseous absorption. 10. The method for determining the composition of ammonium carnallite dewatering material according to claim 5, in the step (c), the formula for calculating the composition of ammonium carnallite dewatering material is: the magnesium chloride content is: [ m ₁ + m ₂ - m ₅ - ( m ₄ /17)*95]/ m ₂ ; Ammonium chloride content is: [ m ₃ +( m ₄ /17)*53.5]/m ₂ ; Magnesium hydroxychloride content is: ( m ₄ /17)* 76.5/ m ₂ ; the water content is: [ m ₁ + m ₂ - m ₃ - m ₄ - m ₅ - ( m ₄ /17)*18]/ m ₂ ; where m ₁ is potassium chloride and sodium chloride m ₂ is the mass of the ammonium carnallite dehydrating material, m ₃ is the mass of the ammonium chloride collected after the reaction, m ₄ is the mass of the ammonia gas absorbed after the reaction, m ₅ is the post-reaction reactor the quality of the material.

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