阅读说明：本技术 一种利用高压釜提取硫酸镁磷渣中钒的方法 (Method for extracting vanadium from magnesium sulfate phosphorus slag by using high-pressure kettle ) 是由 庞君保 周朝辉 甘小强 罗智军 周继伦 于 2021-07-19 设计创作，主要内容包括：本发明公开了一种利用高压釜提取硫酸镁磷渣中钒的方法,包括以下步骤：步骤一、将含钒硫酸镁磷渣、水、氢氧化钠、纯碱和双氧水按以下质量份的配比混合：含钒硫酸镁磷渣,250～350份、水,800～1000份、氢氧化钠,10～20份、纯碱,20～40份、双氧水,50～70份；步骤二、使用高压釜对固液混合物进行搅拌浸出；步骤三、对固液混合物进行固液分离,得滤液A和滤渣A；步骤四、对滤液A加酸调节pH,随后加入硫酸镁净化液进行除磷,反应结束后进行固液分离,得滤液B和滤渣B；步骤五、对滤液B加酸调节pH,随后加入硫酸铵,待晶体析出后静置、过滤获得偏钒酸铵。本发明能在高效提取钒的前提下有效控制工艺成本,达到资源回收利用的最大化。(The invention discloses a method for extracting vanadium from magnesium sulfate phosphorus slag by using an autoclave, which comprises the following steps: step one, mixing vanadium-containing magnesium sulfate phosphorus slag, water, sodium hydroxide, sodium carbonate and hydrogen peroxide according to the following mass part ratio: 250-350 parts of vanadium-containing magnesium sulfate phosphorus slag, 800-1000 parts of water, 10-20 parts of sodium hydroxide, 20-40 parts of soda ash and 50-70 parts of hydrogen peroxide; step two, stirring and leaching the solid-liquid mixture by using a high-pressure kettle; step three, carrying out solid-liquid separation on the solid-liquid mixture to obtain a filtrate A and filter residue A; step four, adding acid into the filtrate A to adjust the pH value, then adding magnesium sulfate purification liquid to remove phosphorus, and carrying out solid-liquid separation after the reaction is finished to obtain filtrate B and filter residue B; and step five, adding acid into the filtrate B to adjust the pH value, then adding ammonium sulfate, standing after crystal precipitation, and filtering to obtain ammonium metavanadate. The method can effectively control the process cost on the premise of efficiently extracting vanadium, and achieves the maximization of resource recycling.)

1. A method for extracting vanadium from magnesium sulfate phosphorous slag by using an autoclave is characterized by comprising the following steps:

step one, mixing vanadium-containing magnesium sulfate phosphorus slag, water, sodium hydroxide, sodium carbonate and hydrogen peroxide according to the following mass part ratio: 250-350 parts of vanadium-containing magnesium sulfate phosphorus slag, 800-1000 parts of water, 10-20 parts of sodium hydroxide, 20-40 parts of soda ash and 50-70 parts of hydrogen peroxide;

step two, stirring and leaching the solid-liquid mixture mixed in the step one by using a high-pressure kettle;

step three, carrying out solid-liquid separation on the solid-liquid mixture after the reaction in the step two to obtain filtrate A and filter residue A;

step four, adding acid into the filtrate A obtained in the step three to adjust the pH value, then adding magnesium sulfate purification liquid to remove phosphorus, and carrying out solid-liquid separation after the reaction is finished to obtain filtrate B and filter residue B;

and step five, adding acid into the filtrate B obtained in the step four to adjust the pH value, then adding ammonium sulfate, standing after crystals are separated out, and filtering to obtain ammonium metavanadate.

2. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 1, wherein the method comprises the following steps: in the first step, the vanadium-containing magnesium sulfate phosphorus slag, water, sodium hydroxide, sodium carbonate and hydrogen peroxide are mixed according to the following mass ratio: 300 parts of vanadium-containing magnesium sulfate phosphorus slag, 900 parts of water, 15 parts of sodium hydroxide, 30 parts of soda ash and 60 parts of hydrogen peroxide.

3. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 2, wherein the method comprises the following steps: when removing phosphorus in the fourth step, firstly adjusting the pH value of the filtrate A to 10, keeping the constant temperature at 40 ℃, stirring at the speed of 300r/min, then adding magnesium sulfate purification solution, controlling the phosphorus removal time within 50min, and after stirring and removing phosphorus, reducing the phosphorus content in the mixed solution to be below 0.05 g/l.

4. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 2, wherein the method comprises the following steps: and controlling the pH value of the filtrate B to be 10 before adding the ammonium sulfate in the fifth step, keeping the constant temperature at 50 ℃, adding the ammonium sulfate, standing for 30min after crystals are separated out, and filtering to obtain the ammonium metavanadate.

5. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 2, wherein the method comprises the following steps: in the second step, the temperature in the high-pressure kettle is 230 ℃, the pressure is 2Mpa, the stirring speed is 500r/min, and the reaction time is 4 hours.

6. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 2, wherein the method comprises the following steps: and the solid-liquid separation in the third step is realized by plate-and-frame filter pressing at the temperature of 50-70 ℃.

7. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 1, wherein the method comprises the following steps: and (3) placing the filter residue A obtained in the third step into hot water of 70-80 ℃ for constant-temperature stirring at the stirring speed of 500r/min for 30min, and performing plate-and-frame filter pressing after the stirring is finished to obtain filtrate C and filter residue C.

8. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 7, wherein the method comprises the following steps: the first step to the fifth step can be repeated, and the filtrate C obtained in the third step is used as a part of water in the next step.

9. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 1, wherein the method comprises the following steps: and C, placing the filter residue B obtained in the fourth step into hot water of 70-80 ℃ for constant-temperature stirring at the stirring speed of 500r/min for 30min, and performing plate-frame filter pressing after the stirring is finished to obtain filtrate D and filter residue D.

10. The method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave as claimed in claim 9, wherein the method comprises the following steps: the first step to the fifth step can be repeated, and the filtrate D obtained in the fourth step is used as a part of water in the first step.

Technical Field

The invention relates to the technical field of vanadium hydrometallurgy, in particular to a method for extracting vanadium from magnesium sulfate phosphorus slag by using a high-pressure kettle.

Background

Vanadium is an important metal element widely applied in the fields of steel, chemical industry, ceramics and even aerospace, and in recent years, the vanadium is an important metal element widely applied in the fields of steel, chemical industry, ceramics and even aerospace. Therefore, effective extraction and recovery of vanadium in various slag generated in the metal smelting process are very important, and the waste of resources and the damage to the environment can be reduced.

The magnesium sulfate phosphorous slag is a slag material formed by phosphorus serving as an impurity element and phosphorus removal by using magnesium sulfate in a separation and enrichment process, has a certain vanadium content, and is easily subjected to vanadium loss because vanadium is wrapped in the phosphorous slag in a sodium vanadate form. At present, the extraction process of vanadium from slag includes two major types, namely a wet process and a fire process, in the wet process, vanadium is recovered from filtrate by adopting an alkali liquor leaching mode, but magnesium sulfate phosphorous slag is used as a special vanadium-containing slag, at present, a method for extracting vanadium from magnesium sulfate phosphorous slag is not targeted, the alkali liquor leaching needs to select a leaching solution with a proper proportion, and the leaching solution is related to the acid consumption required by subsequent pH value adjustment, the pressure of subsequent phosphorus removal and the extraction efficiency of subsequent vanadium, and in addition, the condition parameters of various reactions need to be strictly controlled to enable the selected leaching solution to exert the best effect.

Disclosure of Invention

The invention aims to provide a method for extracting vanadium from magnesium sulfate phosphorus slag by using an autoclave. The method can effectively control the process cost on the premise of efficiently extracting vanadium, and achieves the maximization of resource recycling.

The technical scheme of the invention is as follows: a method for extracting vanadium from magnesium sulfate phosphorous slag by using an autoclave comprises the following steps:

step one, mixing vanadium-containing magnesium sulfate phosphorus slag, water, sodium hydroxide, sodium carbonate and hydrogen peroxide according to the following mass part ratio: 250-350 parts of vanadium-containing magnesium sulfate phosphorus slag, 800-1000 parts of water, 10-20 parts of sodium hydroxide, 20-40 parts of soda ash and 50-70 parts of hydrogen peroxide;

step two, stirring and leaching the solid-liquid mixture mixed in the step one by using a high-pressure kettle;

step three, carrying out solid-liquid separation on the solid-liquid mixture after the reaction in the step two to obtain filtrate A and filter residue A;

step four, adding acid into the filtrate A obtained in the step three to adjust the pH value, then adding magnesium sulfate purification liquid to remove phosphorus, and carrying out solid-liquid separation after the reaction is finished to obtain filtrate B and filter residue B;

and step five, adding acid into the filtrate B obtained in the step four to adjust the pH value, then adding ammonium sulfate, standing after crystals are separated out, and filtering to obtain ammonium metavanadate.

Compared with the prior art, the invention has the beneficial effects that: sodium hydroxide, soda ash and hydrogen peroxide are used for carrying out alkaline oxidation leaching on the phosphorus slag containing vanadium and magnesium sulfate, the use amount of alkali is reduced by selecting a proper solid-liquid ratio, the use amount of acid during the later-stage pH value adjustment of filtrate can be reduced, the cost is effectively reduced, the leaching rate of vanadium in the leaching solution using the ratio is high, the leaching rate of phosphorus can be reduced, and the pressure of subsequent phosphorus removal is reduced.

In the method for extracting vanadium from magnesium sulfate phosphorous slag by using the high-pressure kettle, in the first step, the vanadium-containing magnesium sulfate phosphorous slag, water, sodium hydroxide, sodium carbonate and hydrogen peroxide are mixed according to the following mass part ratio: 300 parts of vanadium-containing magnesium sulfate phosphorus slag, 900 parts of water, 15 parts of sodium hydroxide, 30 parts of soda ash and 60 parts of hydrogen peroxide.

In the method for extracting vanadium from magnesium sulfate phosphorus slag by using the autoclave, when phosphorus is removed in the fourth step, the pH value of the filtrate A is adjusted to 10, the constant temperature is kept at 40 ℃, the filtrate A is stirred at the speed of 300r/min, then magnesium sulfate purifying liquid is added, the phosphorus removal time is controlled within 50min, and after the mixture is stirred for phosphorus removal, the phosphorus content in the mixed liquid is reduced to be below 0.05 g/l.

In the method for extracting vanadium from magnesium sulfate phosphorus slag by using the autoclave, before the ammonium sulfate is added in the fifth step, the pH value of the filtrate B is controlled to be 10, the constant temperature is kept at 50 ℃, after the ammonium sulfate is added, after crystals are separated out, the filtrate B is kept stand for 30min, and then the ammonium metavanadate is obtained by filtering.

In the method for extracting vanadium from magnesium sulfate phosphorus slag by using the high-pressure kettle, in the second step, the temperature in the high-pressure kettle is 230 ℃, the pressure is 2Mpa, the stirring speed is 500r/min, and the reaction time is 4 hours.

In the method for extracting vanadium from magnesium sulfate phosphorous slag by using the high-pressure kettle, solid-liquid separation in the third step is realized by plate-and-frame pressure filtration at the temperature of 50-70 ℃.

In the method for extracting vanadium from magnesium sulfate phosphorous slag by using the autoclave, the filter residue A obtained in the third step is stirred in hot water of 70-80 ℃ at a constant temperature, the stirring speed is 500r/min, the stirring time is 30min, and after the stirring is finished, plate-and-frame filter pressing is carried out to obtain the filtrate C and the filter residue C.

In the method for extracting vanadium from magnesium sulfate phosphorus slag by using the autoclave, the steps from the first step to the fifth step can be repeated, and the filtrate C obtained in the third step is used as a part of water in the next step.

In the method for extracting vanadium from magnesium sulfate phosphorus slag by using the autoclave, the filter residue B obtained in the fourth step is stirred in hot water of 70-80 ℃ at a constant temperature, the stirring speed is 500r/min, the stirring time is 30min, and after the stirring is finished, plate-frame filter pressing is carried out to obtain the filtrate D and the filter residue D.

In the method for extracting vanadium from magnesium sulfate phosphorus slag by using the autoclave, the steps from the first step to the fifth step can be repeated, and the filtrate D obtained in the fourth step is used as a part of water in the next step.

Drawings

FIG. 1 is a schematic flow diagram of the present invention;

FIG. 2 is a diagram of a magnesium sulfate phosphorous slag before vanadium extraction;

FIG. 3 is a diagram of a magnesium sulfate phosphorous slag after vanadium extraction.

Detailed Description

The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.

Example (b): a method for extracting vanadium from magnesium sulfate phosphorous slag by using an autoclave is shown in figure 1 in brief flow, can be repeatedly carried out in a circulating way, and comprises the following steps:

step one, mixing vanadium-containing magnesium sulfate phosphorus slag, water, sodium hydroxide, sodium carbonate and hydrogen peroxide according to the following mass ratio: 300g of vanadium-containing magnesium sulfate phosphorus slag, 900g of water, 15g of sodium hydroxide, 30g of soda ash and 60g of hydrogen peroxide to obtain a solid-liquid mixture.

Step two, stirring and leaching the solid-liquid mixture mixed in the step one by using a high-pressure kettle, controlling the temperature in the high-pressure kettle to be 230 ℃, the pressure to be 2Mpa, the stirring speed to be 500r/min and the reaction time to be 4h, and efficiently extracting vanadium, so that the loss of vanadium in slag is reduced to the minimum, and the maximum resource recycling is achieved;

after the reaction, the heating was stopped, the mixture was stirred until the temperature and pressure were reduced to room temperature and room pressure, and then all the solid-liquid mixture in the autoclave was taken out.

Step three, performing solid-liquid separation on the solid-liquid mixture after the reaction in the step two, maintaining the solid-liquid separation at a liquid temperature of 70 ℃, and separating by adopting a plate-and-frame filter pressing mode to obtain a filtrate A and a filter residue A, wherein the filtrate A is a sodium vanadate solution, and the filter residue A is mainly magnesium hydroxide;

and (2) placing the filter residue A into hot water of 70 ℃ for constant-temperature stirring, wherein the using amount of the hot water is 300ml, the stirring speed is 500r/min, the stirring time is 30min, and after the stirring is finished, carrying out plate-and-frame filter pressing to obtain a filtrate C and a filter residue C, wherein the filtrate C still contains a small amount of phosphorus and vanadium and has a certain temperature, and the filtrate C is used as a part of water in the next step I, so that the cost is reduced, and the recovery rate of the vanadium is improved.

Drying and weighing filter residue C for V before returning filtrate C to the step for reuse₂O₅And phosphorus content analysis, combining filtrate A and filtrate C (but not mixing) and carrying out V₂O₅And the content analysis of phosphorus, the analysis result is as follows:

and selecting the dosage of the magnesium sulfate purification liquid required by the phosphorus removal in the fourth step according to the analysis result, and specifically adding the magnesium sulfate purification liquid for phosphorus removal in a dosage of 2 times of the theoretical value of the consumed magnesium sulfate required by the phosphorus content in the phosphorus slag.

Step four, adding acid into the filtrate A obtained in the step three to adjust the pH value to 10, keeping the temperature constant at 40 ℃, stirring at the speed of 300r/min, adding the calculated magnesium sulfate purifying solution, controlling the phosphorus removal time within 50min, stirring to remove phosphorus, measuring the phosphorus content of the mixed solution to reduce the phosphorus content in the mixed solution to be below 0.05g/l (once four phosphorus removal steps are carried out again until the phosphorus content in the mixed solution reaches the standard after the phosphorus removal is carried out, and carrying out solid-liquid separation by plate-and-frame filter pressing after the reaction is finished to obtain a filtrate B and a filter residue B;

and (3) placing the filter residue B into hot water of 70 ℃ for constant-temperature stirring, wherein the using amount of the hot water is 300ml, the stirring speed is 500r/min, the stirring time is 30min, and after stirring, carrying out plate-frame filter pressing to obtain a filtrate D and a filter residue D, wherein the filtrate D still contains a small amount of phosphorus and vanadium and has a certain temperature, and the filtrate D is used as a part of water in the next step I, so that the cost is reduced, and the recovery rate of the vanadium is improved.

Step five, adding acid into the filtrate B in the step four to adjust the pH value to 10, keeping the temperature at 50 ℃, and then adding ammonium sulfate until NH is achieved₄VO₃Standing for 30min after crystal precipitation, and filtering to obtain ammonium metavanadate.

Filtering to obtain 40.10g of ammonium metavanadate, and analyzing the ammonium metavanadate until the ignition loss is 70.01 percent and the V is higher₂O₅The content is 99.83 percent, and the final product V₂O₅The recovery was 91.32%.

In order to embody the effect of the invention of effectively controlling the process cost on the premise of efficiently extracting vanadium and achieving the maximization of resource recycling, two groups of comparison groups adopting different processes are introduced to be compared with the process of the invention.

Control group 1:

magnesium sulfate phosphorus slag high-temperature roasting and sulfuric acid leaching experiment:

100g of magnesium sulfate phosphorous slag (V) is weighed₂O₅10.23 percent of P and 0.59 percent of P) is roasted at 900 ℃ for 1.5 hours, and the solid-liquid ratio is 1: leaching with sulfuric acid at pH of 0.5-1 under stirring at 70-80 deg.C for 3 hr, filtering, and testing V in the filtrate₂O₅And P results are as follows:

	V2O5	P
			magnesium sulfate phosphorus slag (100g)	10.23％	0.59％
Volume of filtrate (600ml)	12.58g/l	0.6g/l
			Filter residue (50g)	5.08％	0.45％
Recovery ratio of filtrate (%)	75.48％	61.02％

Although the roasting and acid leaching experiments are effective, the using amount of acid is low, the energy consumption is high, and the leaching rate is low.

Control group 2:

heating and extracting by a direct alkaline leaching method:

100g of magnesium sulfate phosphorous slag (V) is weighed₂O₅10.23% of P, 0.59% of P), 60g of sodium hydroxide, boiling, adding about 5ml of hydrogen peroxide dropwise, keeping the temperature at 80 ℃ for 2 hours, and measuring the following results after heat filtration:

	V2O5	P
			magnesium sulfate phosphorus slag (100g)	10.23％	0.59％
Volume of filtrate (700ml)	13.30g/l	0.46g/l
			Filter residue (40g)	2.21％	0.66％
Recovery ratio of filtrate (%)	91.0％	54.58％

Direct alkali extraction of V₂O₅Although the effect is basically satisfactory, the dosage of the caustic soda flakes is large, the dosage is reduced, or the leaching rate is obviously reduced by using different proportions of the sodium carbonate and the caustic soda flakes. To maintain a high leaching rate, a large amount of various alkalis is used, and a certain amount of sulfuric acid is consumed when the pH is subsequently adjusted to 10.

In conclusion, the method reduces energy consumption and acid and alkali consumption compared with the traditional high-temperature roasting method by utilizing liquid-phase oxidative decomposition of the vanadium-containing slag, adds hydrogen peroxide to generate oxygen to promote the vanadium to be completely converted into pentavalent vanadium, utilizes sodium vanadate in the alkali liquor leaching slag to improve the leaching recovery rate of the vanadium, and can achieve water balance by reusing 2 washing solutions of the leaching slag.

In the process method, besides the parameters such as temperature, time, pressure, stirring speed and the like, the proportion of the alkali consumption is more important, and the alkali consumption is not only related to the self consumption and the leaching rate, but also related to the consumption of subsequent acid and the leaching rate of phosphorus.

In this example, 5 different alkali dosage schemes are taken for comparison (the alkali dosage scheme in this example is scheme 4), 300g of the phosphorous slag containing vanadium and magnesium sulfate is treated simultaneously, 900g of water is added, other process parameters are kept the same, and the comparison results of the schemes are as follows:

the alkali consumption ratio of the scheme 1 is 10g of NaOH, 20g of soda and 30g of hydrogen peroxide, the alkali consumption ratio of the scheme 2 is 10g of NaOH, 30g of soda and 30g of hydrogen peroxide, the alkali consumption ratio of the scheme 3 is 10g of NaOH, 30g of soda and 60g of hydrogen peroxide, the alkali consumption ratio of the scheme 4 is 15g of NaOH, 30g of soda and 60g of hydrogen peroxide, and the alkali consumption ratio of the scheme 5 is 15g of NaOH, 45g of soda and 60g of hydrogen peroxide.

Through the experiments of the above sets of schemes, schemes 1, 2 and 3V₂O₅The extraction rate of (2) is low, and both schemes 4 and 5 can obtain ideal V₂O₅The extraction rate (reaching more than 95 percent). Scheme(s)3. 4 and 5 transverse comparison, scheme 5V₂O₅Although the extraction rate is the highest, the consumed sulfuric acid is relatively high, the leaching rate of P is also high, the economic and environmental protection are not sufficient, and the scheme 4 is V₂O₅In case of extraction rate higher than scheme 3, unexpectedly lower P leaching rate was obtained, in comprehensive V₂O₅The leaching conditions of scheme 4 are optimal after the extraction rate, the leaching rate of P, the alkali dosage and the acid dosage are obtained.

Fig. 2 and fig. 3 are respectively a physical diagram of magnesium sulfate phosphorous slag before and after vanadium extraction under the leaching condition of the utilization scheme 4 of the invention, and vanadium in the leached slag after extraction is well dissolved out, so that the reutilization rate of vanadium is high.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned examples, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.