Solvent for dissolving solid potassic salt ore as well as preparation method and application of solvent

Abstract

The invention discloses a solvent for dissolving solid potassic salt ore as well as a preparation method and application thereof, relates to the field of solid potassic salt ore solvents, and particularly aims to solve the problem that in the background technology, the components of solvents for mining different types of potassic salt ore in different regions are greatly different. According to the solvent for dissolving the solid potassic salt ore, when the solvent is used for exploiting soluble potassic salt ore in a big wave beach mining area, the dissolution rate of potassic salt can be guaranteed, meanwhile, it is guaranteed that a rock stratum structure framework is not damaged, and therefore the situation that the stratum structure and the stability of the stratum structure are affected in practical application is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of solid potash ore solvents, and in particular relates to a solvent for dissolving solid potash ore, and a preparation method and application thereof. Background Art

[0002] There are abundant mineral resources in Dalangtan area of ​​Mangya City, Qinghai Province, which are widely distributed. The lithology of the mining area is mainly sulfate rock, the main mineral is soluble potash ore, the symbiotic minerals are rock salt and mirabilite, and the associated minerals are magnesium salt (MgSO4) and polyhalite (K2SO4), which is still difficult to utilize. The main mineral solid soluble potash ore (potash salt, carnallite) is distributed in the Quaternary Holocene strata of Liangbei Depression in Liangzhong deposit, and a small amount is distributed in the upper Pleistocene strata with a relatively stable distribution. The ore body has little change in occurrence and is generally distributed horizontally; the ore body is simple in shape, with layered and quasi-layered distribution; the continuity is good and the extension scale is large; the KCl grade is 0.5% to 19.30%, and it is estimated that the amount of soluble solid potash ore compounds in the area is more than 20 million tons, which is a large potash deposit. The distribution of solid soluble potassium and magnesium salts in this area is strictly restricted by the distribution of Holocene chemical sedimentary layers. Its common paragenetic minerals include rock salt, potassium rock salt, hydrochlorobenzene, and epsom salt. The distribution depth is also shallower than 45m, thus forming carnallite potassium ore and hydrochlorobenzene magnesium ore, potassium rock salt potassium ore, saline clay potassium ore, rock salt potassium ore, epsom salt sodium magnesium alum potassium ore and silt potassium ore from top to bottom.

[0003] At present, the research on the mining method of solid potash ore is mainly based on water dissolution, that is, first use a suitable solvent to convert solid potash ore into liquid ore, and then carry out the subsequent development and utilization steps. Although predecessors have made some explorations in solid-liquid conversion, overall, the research and practice on solid-liquid conversion of salt lakes in China is still in its infancy, with few and scattered studies. Most of the conclusions are simply summaries of statistical laws based on indoor experiments or field experiments, and the control factors are relatively simple. The research objects are also mainly chloride-type deposits (represented by the Chaerhan mining area), and there are few studies on sulfate rock minerals in the Dalangtan area. From the collected public information, it can be seen that the solvents used are mostly magnesium salt solvents or magnesium-sodium mixed solvents. The experimental results are relatively satisfactory, but they are all concerned about the dissolution rate of potassium salts. There is not much description of the dissolution of other minerals. In some field experiments, because the concentration of the prepared solution is low, the content of KCl, NaCl, and MgCl2 is low, so after the dissolution equilibrium reaction is completed, the concentration of each ion increases significantly. However, this solution is not suitable for use as a dissolution-driven solution in industrial production, because too low a NaCl content will cause the solid skeleton in the salt layer to be dissolved, thereby destroying the salt layer and being detrimental to production. In addition, since the dissolution mining experiment itself is highly targeted, the composition of the solvents used for mining different types of potash mines in different regions, different ore layers, and different types of potash mines is quite different. Therefore, when conducting potash mine dissolution experiments in the Dalangtan area, it is not possible to directly use existing solvents with known compositions. Instead, targeted experiments are required to determine the appropriate solvent type and composition range.

[0004] The purpose of the present invention is to study a solvent for dissolving solid potassium salt ore and its preparation method and application, taking the soluble potassium salt in the sulfate rock minerals in the Dalangtan area as the object, so as to dissolve as much potassium salt as possible and dissolve other minerals as little as possible (especially sodium salt), so as to avoid causing greater damage to the stratum during the dissolution mining process. Summary of the invention

[0005] In view of the fact that the solvent compositions used for mining different types of potash ores in different regions, different ore layers, and different background technologies are quite different, the object of the present invention is to provide a solvent for dissolving solid potash ores, wherein the density of the solvent is 1.190 g / mL to 1.210 g / mL, wherein Na + Content is 1.5% to 3.0%, Mg 2+ Content is 4.0% to 5.5%, SO4 2- The content is between 1.5% and 3.5%. The solvent is determined after conducting multiple groups of dissolution tests based on the actual composition characteristics of the soluble potassium salt ore in the Dalangtan mining area. It can ensure the dissolution rate of potassium salt while ensuring that the rock stratum framework will not be damaged.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A solvent for dissolving solid potash ore, characterized in that: the solvent is a solid potash ore dissolving agent prepared by chemical analysis using fresh water, low-potassium solid and old brine, the density of the solid potash ore dissolving agent is 1.190g / mL to 1.210g / mL, and Na + The content is 1.5% to 3.0%, Mg 2+ Content is 4.0% to 5.5%, SO4 2- The content is 1.5%~3.5%.

[0008] Preferably, the Mg 2+ and SO4 2- The content is adjusted and determined according to the phase diagram of the water-salt system, and is used to make the solvent composition reach the composition ratio of the three-phase saturation point of epsom salt Eps, sylvite KCl and carnallite Car in the phase diagram.

[0009] The first object of the present invention is to provide a method for preparing the solvent according to claim 1, comprising the following steps:

[0010] S1. Calculate and determine the mass of fresh water, low potassium solids and old brine according to the required solvent mass;

[0011] S2. According to the result calculated in step S1, weigh the corresponding fresh water, low potassium solid, and old brine respectively;

[0012] S3. Place the low potassium solid into fresh water and stir to dissolve, ensuring complete dissolution and uniform solution;

[0013] S4. The weighed old halogen is slowly added to the solution of step S3 while stirring;

[0014] S5. Take a small amount of the solvent in step S4 for chemical analysis, and determine the Na content in the solvent based on the analysis results. + Mg 2+ 、SO4 2- Whether the content meets the set range, if not, it is necessary to recalculate and supplement the missing raw materials until the Na+, Mg2+, and SO42- contents are within the set range to obtain the final solvent.

[0015] Preferably, in step S5, the solvent contains Na + Mg 2+ 、SO 42- The setting range is: Na + Mg 2+ 、SO 42- The content is greater than 95% of its target content and less than 105% of its target content.

[0016] Preferably, the solvent contains Na + Mg2+ 、SO 42- If the content of Na is not within the set range, the solvent that is not within the set range in step S4 is used as the basis to recalculate and supplement the missing raw materials until it meets the Na + Mg 2+ 、SO4 2- Content requirements.

[0017] The third object of the present invention is to provide an application of the solvent described in claim 1, characterized in that the solvent is used for mining solid potash ore.

[0018] Preferably, the solid potash salt mine is selected from the area where solid potash salt mine is mined in the Dalangtan mining area.

[0019] The beneficial effects of the present invention are as follows: the present invention discloses a solvent for dissolving solid potash ore and its application. Compared with the prior art, the improvements of the present invention are as follows:

[0020] According to the actual composition characteristics of the soluble potash ore in the Dalangtan mining area, the present invention conducts multiple groups of dissolution tests in a targeted manner, and finally determines the solvent of the present invention. When the soluble potash ore in the Dalangtan mining area is mined, the solvent can ensure the potash dissolution rate while ensuring that the rock stratum framework skeleton is not damaged, thereby avoiding affecting the stratum structure and its stability in practical applications. At the same time, the raw materials of the solvent of the present invention are directly selected from the ready-made raw materials in the mining area, the production cost is low, and it is conducive to large-scale promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a physical picture of the sample of the present invention;

[0022] Figure 2 It is a schematic diagram of the test device of the present invention;

[0023] Figure 3 This is a test site diagram of the present invention;

[0024] Figure 4 It is a test flow chart of the present invention;

[0025] Figure 5 is the solvent phase diagram of the present invention; Figure 6 This is a state diagram of the test sample of the present invention after dissolution;

[0026] Among them: 1. solvent barrel; 101. water valve 1; 2. dissolving barrel; 201. water inlet; 202. water outlet valve; 3. water pipe;

[0027] exist Figure 5Among them, Bis is hydrochloric acid magnesia; Car is carnallite; Eps is epsomite; Ast is white sodium magnesium sulfate; Pic is soft potassium magnesium sulfate; KCl is sylvite; Gla is potassium glauber's salt; Na2SO4 is anhydrous glauber's salt. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention but cannot be used to limit the scope of the present invention.

[0029] Example:

[0030] See attached Figure 1-4 The solvent is a solid potassium salt ore dissolving agent prepared by chemical analysis after adding low potassium solid and old brine powder into fresh water and dissolving, and the density of the dissolving agent is 1.190g / mL to 1.210g / mL, wherein Na + Content is 1.5% to 3.0%, Mg 2+ Content is 4.0% to 5.5%, SO4 2- The content is 1.5% to 3.5%;

[0031] The above solvent is used to dissolve solid potash ore, and the solid potash ore is derived from the soluble solid potash ore in the sulfate rock minerals in the Dalangtan mining area; in actual use, it can be combined with Na + , K + Mg 2+ / / Cl - 、SO4 2- —H2O (25℃) water-salt system phase diagram Appropriately adjust the Mg content in the solvent 2+ and SO4 2- The content of potassium hydroxide is increased to make the composition of the dissolved liquid closer to the composition ratio of the three phases of epsom salt (Eps), potassium hydroxide (KCl) and carnallite (Car) in the phase diagram, which is beneficial to subsequent production. The solvent preparation uses the old brine, fresh water and low potassium solids produced by the early evaporation of brine in the mining area as raw materials to achieve recycling.

[0032] The solvent preparation method is as follows:

[0033] S1. Calculate and determine the mass of fresh water, low potassium solids and old brine according to the required solvent mass;

[0034] S2. According to the mass calculated in step S1, weigh the corresponding fresh water, low potassium solid, and old brine respectively;

[0035] S3. Place the low potassium solid into fresh water and stir to dissolve, ensuring complete dissolution and uniform solution;

[0036] S4. Slowly add the weighed old halogen to the solution of step S3, stirring while adding to ensure a uniform solution;

[0037] S5. Take a small amount of the solvent in step S4 for chemical analysis, and determine the Na content in the solvent based on the analysis results. + Mg 2+ 、SO4 2- Whether the content meets the set range in the solvent, Na + Mg 2+ 、SO4 2- The setting range of the content is: greater than 95% and less than 105% of the target content. If it exceeds the set range, the solvent that does not meet the range will be used as the basis to recalculate and supplement the missing raw materials until Na + Mg 2+ 、SO4 2- The content is within the set range to obtain the final solvent.

[0038] The present invention also provides an application of the solvent according to claim 1, wherein the solvent is used for mining solid potash ore, and the solid potash ore is selected in the area where solid potash ore is mined in the Dalangtan mining area.

[0039] In order to verify the effect of the above solvent in solid potash ore, this example provides a water-soluble performance test. The experimental process is as follows: Figure 4 As shown, the water solubility test is a laboratory small-scale static solid-liquid conversion test. The raw materials of the solid potash ore in the test are representative solid potash ore selected from the Dalangtan mining area. Under natural (normal temperature) conditions, the above solvents are used to carry out dissolution tests. The dissolution effect on the solid potash ore is analyzed based on the test results, thereby providing a basic basis for further in-depth research, expanded experimental research, and mineral development and utilization.

[0040] The raw materials of solid potash ore are selected from the solid potash ore in Dalangtan mining area, which has a complex composition, including silt, silt, rock salt, mirabilite, gypsum, Epsom salt and sodium magnesium sulfate. Multiple representative samples (solid potash ore) were selected from Dalangtan mining area according to the ore layer, potash content, potassium resources, etc. for testing, including samples with high, medium and low potash content. The samples were placed in open wooden boxes without sample delivery orders. There were also 4 original solution mining test samples collected on the surface or in the mining pit, such as Figure 1 As shown; the sampling boreholes are 12-QZ5 and DZ1604 respectively. All samples are original samples. Some samples are sealed with tape, and the lengths are different. The unsealed samples are loose blocks or muddy. Sample information cards are nailed to the wooden boxes, and some cards are missing. The test mainly selects sealed packaged samples. The contents of the main elements in the solute samples are shown in Table 1 below. RC-B3 and RC-B4 in the table are surface samples, and the rest are drill core samples.

[0041] Table 1 Main element contents in experimental solute samples

[0042]

[0043]

[0044] It can be seen from Table 1 that the sulfate content in the solute samples of the Dalangtan mining area is generally high, SO4 2- Up to 31.6%.

[0045] Test equipment

[0046] The test was carried out in the testing center of Chai Institute of Integrated Materials. The unit dissolution and conversion test was carried out in a cylindrical transparent organic container, which was customized according to the actual size of the solid potash ore sample. The simple test device is attached. Figure 2 The test site equipment is shown in the attached Figure 3 As shown;

[0047] Specifically, the test device includes: a solvent barrel 1 and a dissolving barrel 2, wherein the solvent barrel 1 is provided with a scale for facilitating calculation of the amount of solvent released, and a water outlet valve 101 is provided at the bottom end of the solvent barrel 1, and a water inlet 201 and a water outlet valve 202 are provided at the bottom end of the dissolving barrel 2, the water inlet 201 is connected with the water valve 101 through a water pipe 3, and is used to introduce the solvent in the solvent barrel 1 into the dissolving barrel 2, the solvent barrel 1 and the dissolving barrel 2 are both transparent, and a solid potash ore sample is placed in the dissolving barrel 2, and during the test, the solid potash ore sample in the dissolving barrel 2 needs to be completely submerged by the solvent, and the solvent barrel 1 is higher than the horizontal plane of the dissolving barrel 2;

[0048] Figure 4 The following is the experimental flow chart. The specific experimental process is as follows:

[0049] S1. Prepare the solvent and pour it into the solvent barrel 1;

[0050] S2. The selected solid potash sample is weighed and its chemical composition is determined, and then slowly placed into the dissolution tank 2;

[0051] S3. Open the outlet valve 101 in sequence, so that the solvent slowly flows into the dissolution barrel 2, until the solvent just does not dissolve the sample in the barrel 2, stop discharging, and the amount of solvent put into the solvent barrel 1 is determined by the scale;

[0052] S4. Collect the dissolved liquid from the outlet valve 202 of the dissolving tank 2 at irregular intervals (collect once every 2 to 3 hours in the initial stage, and gradually extend the collection interval to about 5 to 24 hours later, and the duration of a single sample experiment is 40 to 96 hours) to determine whether it has reached saturation. If it is not saturated, return the dissolved liquid to the tank and continue the experiment. If it is confirmed that it has reached saturation, end this experiment. Because this is a small-scale experiment, the amount of solution is small. Considering the uniformity of the sample, all the dissolved liquid is released each time during collection, and the sample is collected after stirring evenly. Among them, the saturation judgment standard of the dissolved liquid is: if the KCl content in the dissolved liquid is below 0.30%, and the KCl content in the solid is close to the theoretically calculated critical grade of dissolution mining, it is judged to be saturated and the sample experiment is ended, otherwise the experiment is continued;

[0053] S5. Perform density measurement and chemical composition analysis on the saturated dissolved solution.

[0054] Specifically, the density measurement and chemical composition analysis of the saturated solution in step S4 are shown in Table 2. It can be seen from Table 2 that the sodium salt dissolution rate is below 5.24%, and although pores gradually appear during the sample dissolution process, no collapse occurs until the end of the dissolution (see Figure 6 ), which means that the skeleton of the sample was not damaged. The K+ in the results of Table 2 is calculated as KCl, and the key data of each group of experiments are shown in Table 3.

[0055]

[0056]

[0057] It can be seen from Table 3 that the KCl content in the solute is between 0.62% and 16.58%, and the KCl dissolution recovery rate is between 69.14% and 99.71%, with an average of 84.51%. The dissolution rates of the two groups of surface samples are 97.77% and 99.71%, respectively, which are significantly higher than those of the core samples. This is because the pores of the surface samples are larger and the solvent can more easily enter the interior of the sample. The KCl content in the dissolved solution is between 0.31% and 2.04%, which is somewhat low. The KCl content in the solid slag is between 0.10% and 3.68%. Except for a few larger groups, most of them are below 0.50%, and the solute KCl content of the higher groups is also very high. The dissolution can be continued by increasing the number of dissolutions. This time, due to time reasons, it was not continued. The phase diagram index is calculated based on the composition of the dissolved solution. Its position in the phase diagram of the Na+, K+, Mg2+ / / Cl-, SO42-—H2O (25℃) water-salt system is shown in Figure 5 ,Depend on Figure 5It can be seen that the dissolved liquid is near the saturated line of Epsom salt and carnallite, which means that in the subsequent drying process, potassium salt will be precipitated in the form of carnallite, which is more conducive to production. In summary, from the perspective of potassium salt dissolution recovery rate, sodium salt dissolution rate and dissolved liquid, the results are satisfactory.

[0058]

[0059]

[0060]

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[0062]

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[0064]

[0065]

[0066]

[0067]

[0068] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A solvent for dissolving solid potash ore, characterized in that: The solvent is a solid potash ore dissolving agent prepared by chemical analysis using fresh water, low potassium solid and old brine. The density of the solid potash ore dissolving agent is between 1.190 g / mL and 1.210 g / mL, wherein Na + The content is 1.5% to 3.0%, Mg 2+ Content is 4.0% to 5.5%, SO4 2- The content is 1.5%~3.5%.

2. The solvent according to claim 1, characterized in that: The Mg 2+ and SO4 2- The content is adjusted and determined according to the phase diagram of the water-salt system, and is used to make the solvent composition reach the composition ratio of the three-phase saturation point of epsom salt Eps, sylvite KCl and carnallite Car in the phase diagram.

3. A method for preparing the solvent according to claim 1, characterized in that: The steps include: S1. Calculate and determine the mass of fresh water, low potassium solids and old brine according to the required solvent mass; S2. According to the result calculated in step S1, weigh the corresponding fresh water, low potassium solid, and old brine respectively; S3. Place the low potassium solid into fresh water and stir to dissolve, ensuring complete dissolution and uniform solution; S4. The weighed old halogen is slowly added to the solution of step S3 while stirring; S5. Take a small amount of the solvent in step S4 for chemical analysis, and determine the Na content in the solvent based on the analysis results. + Mg 2+ 、SO4 2- Whether the content meets the set range, if not, it is necessary to recalculate and supplement the missing raw materials until Na + Mg 2+ 、SO4 2- The content is within the set range to obtain the final solvent.

4. The method according to claim 3, characterized in that: In step S5, the Na + Mg 2+ 、SO4 2- The setting range is: Na + Mg 2+ 、SO4 2- The content is greater than 95% of its target content and less than 105% of its target content.

5. The method according to claim 4, characterized in that: The Na in the solvent + Mg 2+ 、SO4 2- If the content of Na is not within the set range, the solvent that is not within the set range in step S4 is used as the basis to recalculate and supplement the missing raw materials until it meets the Na + Mg 2+ 、SO4 2- Content requirements.

6. An application of the solvent according to claim 1, characterized in that: The solvent is used to mine solid potash ore.

7. The use according to claim 6, characterized in that: The solid potash salt mine is selected in the area where the solid potash salt mine is mined in the Dalangtan mining area.

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