Method for preparing sludge conditioner from aluminum mud resources and sludge conditioner

Abstract

The present application relates to water purification and sludge treatment technical field, especially to a kind of aluminum mud resource utilization preparation sludge conditioner's method and sludge conditioner.The method includes: (1) hydrochloric acid and aluminum mud are mixed and reacted, and sludge conditioner primary liquid is obtained;(2) sludge conditioner primary liquid is added to precipitant and impurity is removed, then calcium aluminate powder is added to react, and sludge conditioner crude product is obtained;(3) sludge conditioner crude product is pressure filtered, and cooling impurity is removed, and sludge conditioner is obtained.The method provided by the present application realizes the efficient resource utilization of aluminum mud, solves the secondary residue problem caused by the crystallization of sludge conditioner product prepared from aluminum mud, and can effectively improve the dewatering performance of the product on sludge, thereby reducing the overall cost of subsequent sludge disposal, and the process is simple, easy to operate, low in cost, realizes industrial production, and has important economic and environmental significance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water purification and sludge treatment, and particularly relates to a method for preparing a sludge conditioner from aluminum mud resources and the sludge conditioner. BACKGROUND

[0002] Aluminum mud is a solid waste generated in the process of aluminum production and processing, which is composed of fine aluminum particles, inorganic salts, organic additives and moisture. With the increasingly stringent environmental regulations, the treatment and disposal requirements for aluminum mud are becoming higher and higher. At the same time, aluminum mud contains valuable metals such as aluminum resources, which has the potential for recycling. Therefore, the resource utilization of aluminum mud, which converts environmental risks into economic value, has become an important research topic.

[0003] In the existing technology, the conversion of aluminum mud into sludge conditioner by chemical treatment has been proved to realize the recycling of aluminum resources, thereby reducing the disposal pressure of aluminum mud, and also helping to save limited aluminum resources. However, in the process of preparing sludge conditioner products from aluminum mud, there is a crystallization problem, that is, sulfate salt crystallization gradually precipitates and may cause blockage of pipelines, pumps and storage tanks, and seriously affects the stability and use effect of the products. How to solve this crystallization problem is a key problem in the industry, which is still in the experimental stage and has not been applied to actual production.

[0004] Therefore, it is of great economic and environmental significance to develop efficient and low-cost aluminum mud resource utilization technology and solve the crystallization problem. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a method for preparing a sludge conditioner from aluminum mud resources and the sludge conditioner. The method provided by the present application fully utilizes the resource advantage of solid waste aluminum mud as raw material, and innovatively designs the purification process for the crystallization problem of the prepared product, solves the secondary residue problem caused by the crystallization of aluminum mud in the preparation of sludge conditioner products, and effectively improves the dewatering performance of the product on sludge, thereby reducing the overall cost of subsequent sludge disposal, realizing efficient resource utilization of aluminum mud, helping to improve the recycling rate of aluminum mud resources, reducing the adverse effects on the environment, and promoting the technological progress in the field of sludge conditioner. The preparation method is simple in process, easy to operate, low in cost, realizes industrialized production, has wide application prospect, and has important economic and environmental significance.

[0006] In the first aspect, the present application provides a method for preparing a sludge conditioner from aluminum mud resources, which comprises:

[0007] (1) mixing hydrochloric acid with aluminum mud and reacting to obtain a sludge conditioner primary liquid;

[0008] (2) adding a precipitator to the sludge conditioner primary liquid to remove impurities, and then adding calcium aluminate powder to react to obtain a sludge conditioner crude product;

[0009] (3) performing pressure filtration and cooling to remove impurities on the sludge conditioner crude product to obtain the sludge conditioner.

[0010] The method provided by the application substantially solves the problem of subsequent crystallization and precipitation of the sludge conditioner prepared from aluminum sludge, effectively improves the dewatering performance of the product on sludge, reduces the overall cost of subsequent sludge disposal, realizes efficient resource utilization of aluminum sludge, promotes the technical progress in the field of sludge conditioner, and has the advantages of simple process, easy operation, low cost, industrialized production, and wide application prospect, which provides a new solution for the high-efficiency water purifying agent and sludge treatment industry, and has important economic and environmental significance.

[0011] As a preferred technical solution of the application, the salt base of the sludge conditioner primary liquid is-10-10%, for example, -10%, -5%, 5%, 10%, etc.

[0012] When the salt base of the sludge conditioner primary liquid is within the above range of the application, more secondary crystallization residue is removed by filtration, so that the sludge conditioner prepared by the application has more excellent sludge conditioning performance. If the salt base of the sludge conditioner primary liquid does not reach the above index, appropriate amount of hydrochloric acid or aluminum sludge can be added to adjust until the salt base of the sludge conditioner primary liquid reaches the above range.

[0013] As a preferred technical solution of the application, the mass ratio of HCl in the hydrochloric acid to the equivalent aluminum oxide in the aluminum sludge is 1.9-3:1, for example, 1.9:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, etc.

[0014] The preparation method of the sludge conditioner provided by the application has realized industrialized production, and has low requirements on raw materials, wherein the hydrochloric acid can be selected from by-product hydrochloric acid, synthetic hydrochloric acid, etc., and has a wide source and low cost.

[0015] As a preferred technical solution of the application, the mass concentration of the hydrochloric acid is 30-37%, for example, 30%, 32%, 34%, 37%, etc., and is preferably 32%.

[0016] As a preferred technical solution of the application, the equivalent aluminum oxide content in the aluminum sludge is ≥9wt%.

[0017] When the equivalent alumina content in the aluminum mud and the hydrochloric acid concentration are within the above ranges, the mass ratio of the hydrochloric acid to the aluminum mud can be 0.6-1.1:1, such as 0.6:1, 0.8:1, 1.0:1, 1.1:1, etc.

[0018] As a preferred technical solution of the present application, the precipitant is selected from calcium salt or barium salt, and the addition of the precipitant to the primary liquid of the sludge conditioner can form crystals with sulfate in the sludge, thereby reducing the subsequent crystallization and precipitation of sulfate.

[0019] As a preferred technical solution of the present application, the calcium salt includes calcium chloride and / or calcium nitrate.

[0020] As a preferred technical solution of the present application, the barium salt includes barium chloride and / or barium nitrate.

[0021] As a preferred technical solution of the present application, the precipitant is selected from calcium chloride.

[0022] As a preferred technical solution of the present application, the mass ratio of the precipitant to the aluminum mud is 1-2:100, such as 1:100, 1.2:100, 1.4:100, 1.6:100, 1.8:100, 2:100, etc.

[0023] In the present application, the precipitant is added for 30-40 min, and then calcium aluminate powder is added for the basification reaction, so as to provide sufficient time to remove as much sulfate as possible.

[0024] As a preferred technical solution of the present application, the mass ratio of HCl in the hydrochloric acid to the calcium aluminate powder is 1.1-1.8:1, such as 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, etc.

[0025] When the hydrochloric acid concentration is within the above range of 30-37%, the mass ratio of the hydrochloric acid to the calcium aluminate powder can be 3-5:1, such as 3:1, 4:1, 5:1, etc.

[0026] After the preparation of the crude sludge conditioner in the present application, pressure filtration is performed to filter out acid-insoluble residue and precipitated sulfate-insoluble substances, and then cooling and impurity removal are performed.

[0027] As a preferred technical solution of the present application, the method for cooling and impurity removal is that the pressure filtrate obtained by pressure filtration is rapidly cooled to below 75℃ and continuously cooled for 24-48 h, such as 24 h, 30 h, 36 h, 42 h, 48 h, etc., so that the remaining sulfate is fully crystallized and precipitated.

[0028] The present application can accelerate the precipitation of residual sulfate insoluble in the product by cooling and removing impurities from the obtained filter liquor, thereby reducing the subsequent crystallization and precipitation of sulfate in the product, and cooperating with the precipitant to remove impurities, thereby effectively solving the problem of subsequent crystallization and precipitation of the product of the sludge conditioner prepared from aluminum mud.

[0029] As a preferred technical solution of the present application, the method for rapid cooling is water cooling or salt water cooling.

[0030] The filter liquor is rapidly cooled by a cooler device pipeline and flows into a cooling pool for cooling for 24-48 hours, and the cooler can be a graphene tube cooler.

[0031] As a preferred technical solution of the present application, the obtained sludge conditioner is obtained by secondary filtration after the cooling and impurity removal.

[0032] The secondary filtration removes the residual precipitated crystalline impurities, and finally the qualified sludge conditioner product with clear and transparent appearance is obtained.

[0033] As a preferred technical solution of the present application, the temperature of the reaction in step (1) is 60-80℃, for example 60℃, 65℃, 70℃, 75℃, 80℃, etc., and the reaction time is 1.5-3h, for example 1.5h, 2h, 2.5h, 3h, etc.

[0034] As a preferred technical solution of the present application, the temperature of the reaction in step (1) is 70℃, and the reaction time is 2h.

[0035] As a preferred technical solution of the present application, the temperature of the reaction in step (2) is 95-100℃, for example 95℃, 96℃, 97℃, 98℃, 99℃, 100℃, etc., and the reaction time is 1-2h, for example 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2.0h, etc.

[0036] As a specific embodiment of the present application, the method comprises:

[0037] (1) Hydrochloric acid and aluminum mud are metered and added to a reaction kettle, and reacted at 60-80℃ for 1.5-3h to obtain sludge conditioner primary liquid, and the salt base degree is -10-10%;

[0038] (2) A precipitant is added to the sludge conditioner primary liquid to remove impurities, and then calcium aluminate powder is added and reacted at 95-100℃ for 1-2h to obtain sludge conditioner crude product;

[0039] (3) the crude sludge conditioner is subjected to pressure filtration to obtain a pressure filtrate, the pressure filtrate is rapidly cooled to below 75 DEG C by water cooling or brine cooling and continuously cooled for 24-48h to remove impurities, and secondary pressure filtration is performed to obtain the sludge conditioner.

[0040] Preferably, the amount of hydrochloric acid is 30-35% of the volume of the reaction kettle.

[0041] The method provided by the application realizes efficient resource utilization of aluminum sludge, solves the problem of secondary residue caused by crystallization of sludge conditioner products prepared from aluminum sludge, and has the advantages of simple process, easy operation, low cost, industrialized production, important economic and environmental significance, etc.

[0042] In a second aspect, the application provides a sludge conditioner prepared by the method of the first aspect.

[0043] As a preferred technical solution of the application, the content of aluminum oxide in the sludge conditioner is 9-13wt%, such as 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, etc., and the base degree is 55-70%, such as 55%, 60%, 65%, 70%, etc.

[0044] Compared with the prior art, the technical solution provided by the embodiments of the application has the following advantages:

[0045] The method provided by the application makes full use of the resource advantage of solid waste aluminum sludge as raw material, and innovatively designs the purification process for the crystallization problem of the prepared product, solves the problem of secondary residue caused by crystallization of sludge conditioner products prepared from aluminum sludge, effectively improves the dewatering performance of the product on sludge, thereby reducing the overall cost of subsequent sludge disposal, realizes efficient resource utilization of aluminum sludge, helps to improve the recycling rate of aluminum sludge resources, reduces the adverse effects on the environment, promotes the technical progress in the field of sludge conditioner, has the advantages of simple process, easy operation, low cost, industrialized production, wide application prospect, important economic and environmental significance, etc. DETAILED DESCRIPTION

[0046] In order to more clearly understand the above-mentioned purposes, features and advantages of the application, the solutions of the application will be further described below. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other without conflict.

[0047] In the following description, many specific details are set forth in order to provide a thorough understanding of the application, but the application can also be implemented in other ways different from those described herein; obviously, the examples in the specification are only some of the embodiments of the application, not all the embodiments.

[0048] The present application relates to the determination of the content of alumina and the base exchange capacity, and provides a method for determining the content of alumina and the base exchange capacity:

[0049] 1. Determination of the content of alumina

[0050] 1.1 Method summary

[0051] The sample is depolymerized with nitric acid, and an excess of disodium ethylenediaminetetraacetate solution is added at a pH of about 3 to complex with aluminum ions. Dimethylphenyl orange is used as an indicator, and the excess disodium ethylenediaminetetraacetate solution is back-titrated with a zinc chloride standard titration solution.

[0052] 1.2 Analysis steps:

[0053] About 8 g of liquid sample or 2.5 g of solid sample is weighed to the nearest 0.2 g. It is dissolved in deionized water and transferred to a 250 mL volumetric flask, diluted to the mark, and shaken well. The supernatant is sample A.

[0054] 10 mL of sample A is pipetted into a 250 mL conical flask, 10 mL of nitric acid solution is added, and it is boiled for one minute. After cooling to room temperature, 20 mL of EDTA is added, 3-4 drops of thymol blue solution are added, and it is neutralized with ammonia solution until the test solution changes from red to yellow. It is boiled for two minutes. After cooling, 10 mL of acetic acid-sodium acetate buffer solution and 2 drops of dimethylphenyl orange indicator are added, 50 mL of water is added, and it is titrated with a zinc chloride standard solution until the solution changes from light yellow to reddish, while a blank is prepared.

[0055] 1.3. Result calculation:

[0056]

[0057] where

[0058] V0: volume of zinc chloride consumed by the blank, mL;

[0059] V: volume of zinc chloride consumed by the sample, mL;

[0060] c: concentration of the zinc chloride titration solution, mol / L;

[0061] m: mass of the sample, g;

[0062] M: molar mass of alumina, g / mol (M = 101.96);

[0063] V1: volume of sample A pipetted, mL (V1 = 5);

[0064] V A : total volume of sample A, mL (V A = 250).

[0065] 2. Determination of the base exchange capacity

[0066] 2.1 Method summary

[0067] An excess of hydrochloric acid solution is added to the sample, potassium fluoride is added to mask the aluminum ions and iron ions, and an excess of the hydrochloric acid solution is back-titrated with a sodium hydroxide standard titration solution.

[0068] 2.2 Analysis steps

[0069] A 25 mL aliquot of the test solution A (sample to be tested) is placed in a 250 mL conical flask, 20 mL of a hydrochloric acid standard solution is added, a watch glass is placed on top, and the flask is heated on an electric stove until boiling, after which it is immediately removed and allowed to cool to room temperature. Five drops of phenothalin indicator solution are added after the solution has been shaken, and the solution is immediately titrated with a sodium hydroxide standard titration solution until the solution turns a light red color, which is the end point. A blank test is performed at the same time using carbon dioxide-free water.

[0070] 2.3. Result calculation:

[0071]

[0072] where:

[0073] V0: the value of the volume of sodium hydroxide standard titration solution consumed in the blank test, (mL);

[0074] V: the value of the volume of sodium hydroxide standard titration solution consumed in the test sample, (mL);

[0075] c: the accurate value of the actual concentration of the sodium hydroxide standard titration solution, (mol / L);

[0076] M: the value of the molar mass of the hydroxide ion, (g / mol), (M = 16.99);

[0077] m: the value of the mass of the test sample, (g);

[0078] w1: the mass fraction of aluminum oxide measured above, %;

[0079] V1: the value of the volume of the test solution A aliquot, (mL), (V1 = 25);

[0080] V A : the value of the total volume of the test solution A, (mL), (V A = 250);

[0081] M1: the value of the molar mass of aluminum, (g / mol), (M1 = 26.98);

[0082] M2: the value of the molar mass of aluminum oxide, (g / mol), (M2 = 101.96).

[0083] Example 1

[0084] This embodiment provides a method for preparing a sludge conditioner through the resource utilization of aluminum sludge, and the sludge conditioner itself. This embodiment utilizes a sludge conditioner production line from an environmental protection company in Shandong Province. The main equipment on the production line is 50m². 3 Two reactors, 30m 3 One reactor, 200m³ 2 One filter press. Before starting operation, ensure that all relevant valves (including the inlet and outlet valves of the hydrochloric acid feed pump, the outlet valve of the hydrochloric acid storage tank, the valves of the hydrochloric acid feed pipeline on the reactor, and the valves of the acid mist absorption pipeline) are in the open position.

[0085] The method includes the following steps:

[0086] (1) Open all relevant valves and start the hydrochloric acid feed pump to 50m 3 18.5 tons of 32% hydrochloric acid (33.2% of the reactor capacity) were metered and added into the reactor. The agitator in the reactor was activated, and 22.4 tons of aluminum sludge (equivalent to 10.5% alumina) in ton bags was metered and added to the reactor using a trolley system (hydrochloric acid:aluminum sludge mass ratio = 0.83:1). The reactor temperature was controlled at 65℃, and the aluminum sludge and hydrochloric acid reacted in the reactor for 1.5 hours. After the reaction, a sample of the sludge conditioner solution was sent to the laboratory for analysis of alumina and basicity. The results showed an alumina content of 5.47% and a basicity of -5.35%, meeting the subsequent production targets (basicity within ±10%).

[0087] (2) Continue to add 225 kg of calcium chloride to the reactor and continue stirring for 0.5 h. This will precipitate some of the sulfate ions and reduce the subsequent precipitation of sulfate crystals.

[0088] (3) 5t of calcium aluminate powder was added to the reactor sequentially using a crane system (at a mass ratio of hydrochloric acid to calcium powder of 3.7:1). The reaction temperature was controlled at 95℃ and the reaction time was controlled at 1.5h. After the reaction was completed, crude sludge conditioner was obtained.

[0089] (4) The crude sludge conditioner in the reactor is fed into a filter press for one-time filtration. The final product of the filtrate is rapidly cooled to 72°C through the water-cooled cooler pipeline and then flows into the cooling pool for continuous cooling for 24 hours to allow the sulfate to cool and crystallize out as soon as possible.

[0090] (5) The product obtained in step (4) is pumped back into the filter press for secondary filtration. The secondary filtrate flows by gravity into the product storage tank, thus obtaining a clear and transparent sludge conditioner product. Sludge conditioner product quality control: alumina content 10.10%, basicity 60.21%.

[0091] Example 2

[0092] The present embodiment provides a method for preparing a sludge conditioner from aluminum mud resources and a sludge conditioner. The present embodiment is produced by a sludge conditioner production line of a certain environmental protection enterprise in Shandong. The main equipment on the production line is 50m 3 2 sets of reaction kettles, 30m 3 1 set of reaction kettle, 200m 2 1 set of filter press. Before starting the operation, ensure that all relevant valves (including hydrochloric acid inlet pump, outlet valve, hydrochloric acid storage tank outlet valve, hydrochloric acid inlet pipeline valve on the reaction kettle, and acid mist absorption pipeline valve) are in the open state.

[0093] The method comprises the following steps:

[0094] (1) Open all relevant valves, start the hydrochloric acid feeding pump, and add 10.62t of 33% mass fraction hydrochloric acid (add 30.0% of the reaction kettle capacity) to the 30m 3 reaction kettle. Start stirring in the reaction kettle. Use the crane system to add 15.4t of aluminum mud in the form of a ton bag (equivalent to 9.5% of the mass content of aluminum oxide) to the reaction kettle (add according to the mass ratio of hydrochloric acid: aluminum mud = 0.69:1). Control the reaction kettle temperature to 75℃, and the aluminum mud and hydrochloric acid react in the reaction kettle for 2.0h. After the reaction is completed, take the sludge conditioner primary liquid in the reaction kettle to the laboratory for testing of the aluminum oxide and salt base indicators. The test results are that the aluminum oxide content is 5.53%, and the salt base is 0.88%, which meets the subsequent production indicators (salt base ±10%).

[0095] (2) Continue to add 250Kg of calcium chloride to the reaction kettle, and continue to stir for 0.5h. Precipitate part of the sulfate radical, and reduce the subsequent sulfate crystallization.

[0096] (3) Add 3t of calcium aluminate powder to the reaction kettle in turn using the crane system (add according to the mass ratio of hydrochloric acid: calcium powder = 3.54:1), and control the reaction temperature to 95℃ and the reaction time to 1.5h. After the reaction is completed, the sludge conditioner crude product is obtained.

[0097] (4) The final product of the filter press is rapidly cooled to 70℃ by the water cooling cooler pipeline, and then flows into the cooling pool for continuous cooling for 24h to make the sulfate cool and crystallize as soon as possible.

[0098] (5) Pump the product obtained in step (4) into the filter press again for secondary filtration. The secondary filter press liquid product flows into the product storage pool by itself, and the clear and transparent sludge conditioner product is obtained. The product control of the sludge conditioner is that the aluminum oxide content is 9.74%, and the salt base is 66.37%.

[0099] Example 3

[0100] This embodiment provides a method for preparing a sludge conditioner through the resource utilization of aluminum sludge, and the sludge conditioner itself. This embodiment utilizes a sludge conditioner production line from an environmental protection company in Shandong Province. The main equipment on the production line is 50m². 3 Three reactors, 100m³ 2 Two filter presses. Before starting operation, ensure that all relevant valves (including the inlet and outlet valves of the hydrochloric acid feed pump, the outlet valve of the hydrochloric acid storage tank, the valves of the hydrochloric acid feed pipeline on the reactor, and the valves of the acid mist absorption pipeline) are in the open position.

[0101] The method includes the following steps:

[0102] (1) Open all relevant valves and start the hydrochloric acid feed pump to 50m 3 19.47t of 31% hydrochloric acid (33.0% of the reactor capacity) was metered and added into the reactor. The agitator in the reactor was activated, and 17.8t of aluminum sludge (equivalent to 11% alumina content) in ton bags was metered and added to the reactor using a trolley system (hydrochloric acid:aluminum sludge mass ratio = 1.09:1). The reactor temperature was controlled at 70℃, and the aluminum sludge and hydrochloric acid reacted in the reactor for 2.0h. After the reaction, a sample of the sludge conditioner solution from the reactor was sent to the laboratory for analysis of alumina and basicity. The results showed an alumina content of 6.21% and a basicity of -7.82%, meeting the subsequent production targets (basicity within ±10%).

[0103] (2) Continue to add 300 kg of calcium chloride to the reactor and continue stirring for 0.5 h. This will precipitate some of the sulfate ions and reduce the subsequent precipitation of sulfate crystals.

[0104] (3) 4t of calcium aluminate powder was added to the reactor sequentially using a crane system (according to the mass ratio of hydrochloric acid to calcium powder = 4.87:1). The reaction temperature was controlled at 95℃ and the reaction time was controlled at 1.5h. After the reaction was completed, crude sludge conditioner was obtained.

[0105] (4) The crude sludge conditioner in the reactor is fed into a filter press for one-time filtration. The final product of the filtrate is rapidly cooled to 72°C through the water-cooled cooler pipeline and then flows into the cooling pool for continuous cooling for 48 hours to allow the sulfate to cool and crystallize out as soon as possible.

[0106] (5) The product obtained in step (4) is pumped back into the filter press for secondary filtration. The secondary filtrate flows by gravity into the product storage tank, thus obtaining a clear and transparent sludge conditioner product. Sludge conditioner product quality control: alumina content 10.26%, basicity content 58.11%.

[0107] Example 4

[0108] The present embodiment provides a method for preparing a sludge conditioner from aluminum mud resources and a sludge conditioner. The present embodiment is produced by a sludge conditioner production line of a certain environmental protection enterprise in Shandong. The main equipment on the production line is 40m 3 2 sets of reaction kettles, 80m 2 2 filter presses. Before starting the operation, ensure that all relevant valves (including hydrochloric acid feed pump inlet and outlet valves, hydrochloric acid storage tank outlet valve, hydrochloric acid feed pipe valve on the reaction kettle, and acid mist absorption pipe valve) are in the open state.

[0109] The method comprises the following steps:

[0110] (1) Open all relevant valves, start the hydrochloric acid feed pump, and add 18.01 tons of 30% mass fraction hydrochloric acid to the reaction kettle (add 35.0% of the reaction kettle capacity). 3 Start stirring in the reaction kettle. Use the crane system to add 21.5 tons of aluminum mud in the form of a ton bag (equivalent to 13% aluminum oxide mass content) to the reaction kettle (add according to the mass ratio of hydrochloric acid to aluminum mud = 0.84:1). Control the reaction kettle temperature to 70°C, and let the aluminum mud and hydrochloric acid react in the reaction kettle for 3.0h. After the reaction is completed, take the sludge conditioner primary liquid in the reaction kettle to the laboratory to test the aluminum oxide and salt base indicators. The test results are 9.25% aluminum oxide content and 1.30% salt base content, which meet the subsequent production indicators (salt base ±10%).

[0111] (2) Continue to add 250kg of calcium chloride to the reaction kettle and continue to stir for 1.0h. Precipitate part of the sulfate radical to reduce the subsequent sulfate crystallization.

[0112] (3) Measure 4 tons of calcium aluminate powder and add it to the reaction kettle using the crane system (add according to the mass ratio of hydrochloric acid to calcium powder = 4.50:1), and control the reaction temperature to 95°C and the reaction time to 1.5h. After the reaction is completed, the sludge conditioner crude product is obtained.

[0113] (4) The sludge conditioner crude product in the reaction kettle is pumped into the filter press for primary filtration. The filter press liquid end product is rapidly cooled to 68°C by a water cooling cooler pipeline and then flows into a cooling pool for continuous cooling for 36h to make the sulfate crystallize as soon as possible.

[0114] (5) The product obtained in step (4) is pumped into the filter press again for secondary filtration. The secondary filter press liquid product flows into the product storage pool by itself, and the clear and transparent sludge conditioner product is obtained. The sludge conditioner product quality control: aluminum oxide content 12.81%, salt base content 55.45%.

[0115] Example 5

[0116] The embodiment provides a method for preparing sludge conditioner by utilizing aluminum mud resources and the sludge conditioner, and the embodiment is produced by using the sludge conditioner production line in the embodiment 1.

[0117] The method in the embodiment is the same as that in the embodiment 1, and the difference between the embodiment and the embodiment 1 is that, in the embodiment, the base of the sludge conditioner in the first liquid is -25% in step (1).

[0118] It is found that the sludge conditioner crude product in the reaction kettle cannot be pumped into the filter press for primary filtration, and the secondary crystallization residue still exists in the sludge conditioner crude product, that is, the clear and transparent sludge conditioner product cannot be obtained.

[0119] Embodiment 6

[0120] The embodiment provides a method for preparing sludge conditioner by utilizing aluminum mud resources and the sludge conditioner, and the embodiment is produced by using the sludge conditioner production line in the embodiment 1.

[0121] The method in the embodiment is the same as that in the embodiment 1, and the difference between the embodiment and the embodiment 1 is that, in the embodiment, the dosage of the aluminum mud is 12.3t.

[0122] It is found that the dosage of the aluminum mud is small, the base of the sludge conditioner in the first liquid is -34%, 6t of the aluminum mud is continuously added, and the reaction is continuously carried out for 2h, then the first liquid base content is measured again after the reaction is completed, until the base is between -10% and 10%.

[0123] Embodiment 7

[0124] The embodiment provides a method for preparing sludge conditioner by utilizing aluminum mud resources and the sludge conditioner, and the embodiment is produced by using the sludge conditioner production line in the embodiment 1.

[0125] The method in the embodiment is the same as that in the embodiment 1, and the difference between the embodiment and the embodiment 1 is that, in the embodiment, the dosage of the calcium aluminate powder is 3t.

[0126] It is found that the product control index of the finally obtained clear and transparent sludge conditioner product is 9.2%, and the base is 40%, which cannot reach the product control range.

[0127] Embodiment 8

[0128] The embodiment provides a method for preparing sludge conditioner by utilizing aluminum mud resources and the sludge conditioner, and the embodiment is produced by using the sludge conditioner production line in the embodiment 1.

[0129] The method in the embodiment is the same as that in the embodiment 1, and the difference between the embodiment and the embodiment 1 is that, in the embodiment, the dosage of the calcium aluminate powder is 9t.

[0130] The result shows that the sludge conditioner crude product in the reaction kettle cannot be pumped into the filter press for primary pressure filtration, i.e. cannot be filtered, and the secondary crystallization residue still exists in the sludge conditioner crude product, and a clear and transparent sludge conditioner product cannot be obtained.

[0131] Comparative Example 1

[0132] The present comparative example provides a method for preparing a sludge conditioner from aluminum mud resources and the sludge conditioner, and the present comparative example is produced by using the sludge conditioner production line of Example 1.

[0133] The method of the present comparative example is the same as that of Example 1, and the difference between the present comparative example and Example 1 is that step (2) is omitted in the present comparative example.

[0134] The result shows that the sludge conditioner obtained finally still has crystallization residue precipitated, which affects the sludge conditioning performance of the product.

[0135] Comparative Example 2

[0136] The present comparative example provides a method for preparing a sludge conditioner from aluminum mud resources and the sludge conditioner, and the present comparative example is produced by using the sludge conditioner production line of Example 1.

[0137] The method of the present comparative example is the same as that of Example 1, and the difference between the present comparative example and Example 1 is that steps (4) and (5) are omitted in the present comparative example, and the pressure filtration liquid is directly used as the final product.

[0138] The result shows that the sludge conditioner obtained finally still has crystallization residue precipitated, which affects the sludge conditioning performance of the product.

[0139] It should be noted that, in this document, relational terms such as“first” and“second”, and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms“comprises”,“comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by“comprises a...” does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0140] The foregoing is considered as illustrative only of the principles of the application. Numerous modifications and changes will readily occur to those skilled in the art, and it is intended to embrace all such modifications and changes that fall within the scope of the application. Accordingly, the application is not to be restricted in scope to the specific embodiments disclosed herein but is to be accorded the full scope that the principles and novel features request appropriately granted.

Claims

1. A method for preparing a sludge conditioner from aluminum mud resource utilization, characterized in that, The method comprises: (1) mixing hydrochloric acid with aluminum mud and reacting to obtain a sludge conditioner primary liquid; (2) adding a precipitant to the sludge conditioner primary liquid to remove impurities, and then adding calcium aluminate powder to react to obtain a sludge conditioner crude product; (3) performing pressure filtration and cooling to remove impurities on the sludge conditioner crude product to obtain the sludge conditioner; The sludge conditioner primary liquid has a base degree of -10% to 10%; The precipitant is selected from calcium salts or barium salts, the calcium salts include calcium chloride and / or calcium nitrate, and the barium salts include barium chloride and / or barium nitrate; The method for cooling to remove impurities is to rapidly cool the pressure filtrate obtained by pressure filtration to below 75°C and continuously cool for 24 to 48 hours, so that the remaining sulfate in the pressure filtrate is fully crystallized and precipitated.

2. The method of claim 1, wherein, The mass ratio of HCl in the hydrochloric acid to the equivalent aluminum oxide in the aluminum mud is 1.9 to 3:1; and / or, the equivalent aluminum oxide content in the aluminum mud is ≥9 wt%.

3. The method according to claim 1 or 2, characterized in that, The mass ratio of the precipitant to the aluminum mud is 1 to 2:

100.

4. The method according to claim 1 or 2, characterized in that, The mass ratio of HCl in the hydrochloric acid to the calcium aluminate powder is 1.1 to 1.8:

1.

5. The method of claim 1, wherein, The method for rapid cooling is to use water cooling or salt water cooling to cool.

6. The method of claim 1 or 2, wherein, After the cooling to remove impurities, secondary pressure filtration is performed to obtain the sludge conditioner.

7. The method of claim 1 or 2, wherein, In step (1), the reaction temperature is 60 to 80°C, and the reaction time is 1.5 to 3 hours; And / or, in step (2), the reaction temperature is 95 to 100°C, and the reaction time is 1 to 2 hours.

8. A sludge conditioner characterized by, The sludge conditioner is prepared by the method of any one of claims 1 to 7.

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