CN102936660B - Method for leaching vanadium from vanadous stone coal roasting slag - Google Patents

Abstract

The invention relates to a process for leaching vanadium pentoxide from vanadium-containing stone coal, which includes the following steps: 1) crushing, ball milling, and grading to obtain fine-grained products and coarse-grained products; 2) using dilute sulfuric acid solution to Fine-grained products are leached to obtain dilute acid leachate; 3) Coarse-grained products are flotationd to obtain flotation concentrates; 4) Sulfuric acid solution is used to leach flotation concentrates to obtain strong acid leachate; 5) Dilute acid The leaching solution and the strong acid leaching solution are subjected to impurity removal, extraction, vanadium precipitation and calcination processes to obtain the product. The present invention has the following effects: ① Dilute sulfuric acid is used for leaching fine-grained grades, with low acid consumption and high leaching rate. ② Flotation is carried out on the graded coarse-grained products, which improves the grade of vanadium and reduces the amount of materials entering the leaching process. ③Dilute acid leaching is used for fine-grained grades, and strong acid leaching is used for difficult-to-leach flotation concentrates, with less impurity leaching, which reduces the difficulty of subsequent purification and removal of impurities and the consumption of reagents. ④It can increase the recovery rate of vanadium by 4%~8%.

Description

Method for leaching vanadium from vanadium-containing stone coal roasting slag

technical field

The invention relates to leaching vanadium pentoxide from vanadium-containing stone coal, in particular to a process of classifying, flotation and then leaching vanadium-containing stone coal roasting slag.

Background technique

Most of the existing technologies for extracting vanadium from vanadium-containing stone coal are to roast the ore at a certain temperature for a certain period of time, and then use acid or alkali solution to leach the roasted slag, so that vanadium enters the solution, and then use solvent extraction or The method of ion exchange increases the concentration of vanadium in the solution, and finally vanadium is deposited. During the leaching process, because the material contains more acid-consuming or alkali-consuming substances, the consumption of leaching reagents is large and the cost of leaching is high. And due to the high concentration of acid or alkali, a large amount of impurities will be leached, which will increase the difficulty of subsequent purification steps. If the material can be pretreated before leaching, part of the tailings can be discarded in advance, and the vanadium grade can be improved, the consumption of reagents can be greatly reduced, the difficulty of purifying and removing impurities in the leachate can be reduced, and the production cost can be reduced.

Contents of the invention

The purpose of the present invention is to provide an effective method for leaching vanadium from vanadium-containing stone coal roasting slag, through classification and flotation, discarding part of tailings, improving vanadium grade, reducing reagent consumption, reducing production costs, and increasing vanadium Recovery rate.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is: the method for leaching vanadium from vanadium-containing stone coal roasting slag, is characterized in that comprising the following steps:

1) First crush the stone coal roasting slag, and then use a ball mill to grind it until the particle size is less than -200 mesh, accounting for 75~95%, and classify the grinding slurry to obtain fine-grained products and coarse-grained products. Fine-grained products The upper limit of the particle size of the product is 400 mesh to 300 mesh;

2) Leach fine-grained products with dilute sulfuric acid solution, the liquid-solid ratio is 3~6:1, the concentration of dilute sulfuric acid is 0.5%~5%, the leaching temperature is 65~95°C, and the leaching time is 2h~8h, and dilute acid leaching solution;

3) Flotation is carried out on coarse-grained products to obtain flotation concentrates;

4) Leach the flotation concentrate with sulfuric acid solution, the sulfuric acid concentration is 10%~30%, the leaching temperature is 65~95°C, the leaching time is 4h~12h, and the liquid-solid ratio is 3~6:1 to obtain a strong acid leachate;

5) The dilute acid leaching solution obtained in step 2) and the strong acid leaching solution obtained in step 4) undergo purification and removal of impurities, extraction or ion exchange adsorption and desorption, vanadium precipitation, and calcination to obtain vanadium pentoxide products.

According to the above scheme, the flotation collector used in the flotation is a mixture of dodecylamine and oleylamine, the mass ratio of dodecylamine to oleylamine is 2~5:1, and the consumption of the flotation collector is 100g/ t~300g/t (refers to 100-300g collector per ton of coarse-grained product).

According to the above scheme, water glass is added as an inhibitor during the flotation process, and the inhibitor dosage is 80g/t~320g/t (refers to 80-320g inhibitor per ton of coarse-grained product). the

Compared with the prior art, the present invention has the following advantages and effects:

① First classify the stone coal roasting slag after grinding to separate the fine-grained grade, and use low-concentration dilute sulfuric acid to leach the fine-grained grade, which has low acid consumption and high leaching rate;

② Carry out flotation on the graded coarse-grained products, improve the grade of vanadium, discard part of the tailings, reduce the amount of materials entering the leaching process, and further reduce the acid consumption;

③ Dilute acid leaching is used for the easy-to-leach fine-grained grade, and strong acid leaching is used for the difficult-to-leach flotation concentrate, so that the leaching of impurities is less, which reduces the difficulty of subsequent purification and removal of impurities and the consumption of reagents;

④ Under the same conditions, the present invention can improve the vanadium recovery rate by 4% to 8%;

⑤ The obtained flotation tailings are not acidic and can be used to produce building materials, improving resource utilization.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the examples, but this description will not constitute a limitation to the present invention.

Example 1

Roasting slag of vanadium-containing stone coal in a certain place in Shaanxi, the content of vanadium pentoxide is 0.98%, as shown in Figure 1, the ore is crushed and ball-milled, and the content of -200 mesh in the ball-milled product is 76.23%, and then classified to separate -400 mesh fine particles Grade products and +400 mesh coarse-grained products. -400 mesh fine-grained products are leached with 1% sulfuric acid at 75°C for 4 hours, the liquid-solid ratio is 4:1, and the leaching rate is 90.15%. For flotation of +400 mesh coarse-grained products, the collector is a mixture of dodecylamine and oleylamine, the mass ratio of dodecylamine and oleylamine is 2:1, the amount of collector is 200g/t, and the inhibitor is Water glass, dosage 120g/t. After a rough separation, the vanadium pentoxide grade of the flotation concentrate is 1.41%, and the flotation recovery rate is 88.39%. The flotation concentrate is leached with 20% sulfuric acid, the leaching temperature is 95°C, the leaching time is 8h, the liquid-solid ratio is 4:1, and the leaching rate is 87.96%. Combining fine-grain product leaching solution with flotation concentrate leaching solution, purifying and removing impurities, resin adsorption, desorption, vanadium precipitation, and calcination to obtain vanadium pentoxide product. The total recovery rate of vanadium in the whole process is 77.89%. Compared with the direct acid leaching of roasting slag, the recovery rate of vanadium is increased by 4.53%.

Example 2

Vanadium-containing stone coal roasting slag in a certain place in Hubei, the content of vanadium pentoxide is 1.05%, the ore is crushed and ball-milled, and the content of -200 mesh in the ball-milled product is 88.41%, and then classified to separate -400 mesh fine-grained products and + 400 mesh coarse-grained products. -400 mesh fine-grained products were leached with 2% sulfuric acid at 85°C for 3 hours, the liquid-solid ratio was 4:1, and the leaching rate was 90.51%. For flotation of +400 mesh coarse-grained products, the collector is a mixture of dodecylamine and oleylamine, the mass ratio of dodecylamine and oleylamine is 3:1, the amount of collector is 180g/t, and the inhibitor is Water glass, dosage 150g/t. After a rough separation, the vanadium pentoxide grade of the flotation concentrate is 1.65%, and the flotation recovery rate is 89.24%. The flotation concentrate is leached with 25% sulfuric acid, the leaching temperature is 95°C, the leaching time is 5h, the liquid-solid ratio is 4:1, and the leaching rate is 88.85%. Combining fine-grained product leaching solution with flotation concentrate leaching solution, purifying and removing impurities, resin adsorption, desorption, vanadium precipitation, and calcination to obtain vanadium pentoxide product. The total recovery rate of vanadium in the whole process is 76.11%. Compared with the direct acid leaching of roasting slag, the recovery rate of vanadium is increased by 5.62%.

Claims (3)

1. the method for leaching vanadium from Rock coal containing alum fired slags, is characterized in that including following steps:

1) first bone coal fired slags is carried out to fragmentation, then with ball mill, be milled to granularity and be less than 200 orders and account for 75 ~ 95%, ore grinding ore pulp is carried out to classification, obtain fine fraction product and coarse fraction product, in the granularity of fine fraction product, be limited to 400 orders;

2) with dilution heat of sulfuric acid, fine fraction product is leached, liquid-solid ratio is 3 ~ 6:1, and dilute sulphuric acid concentration is 0.5% ~ 5%, and extraction temperature is 65 ~ 95 ℃, and extraction time 2h ~ 8h obtains diluted acid leaching liquid;

3) coarse fraction product is carried out to flotation, obtain flotation concentrate;

4) with sulphuric acid soln, flotation concentrate is leached, sulfuric acid concentration is 10% ~ 30%, and extraction temperature is 65 ~ 95 ℃, extraction time 4h ~ 12h, and liquid-solid ratio is 3 ~ 6:1, obtains strong acid leach liquor;

5) step 2) gained diluted acid leaching liquid and step 4) gained strong acid leach liquor, after purification and impurity removal, extraction or ion-exchange absorption and desorb, precipitation, calcination process, obtain Vanadium Pentoxide in FLAKES product.

According to claim 1 from Rock coal containing alum fired slags the method for leaching vanadium, it is characterized in that the flotation collector that the flotation described in step 3) adopts is amino dodecane and oleyl amine mixture, amino dodecane and oleyl amine mass ratio are 2 ~ 5:1, and the consumption of flotation collector is 100g/t ~ 300g/t.

According to claim 2 from Rock coal containing alum fired slags the method for leaching vanadium, it is characterized in that adding water glass as inhibitor in floatation process, inhibitor consumption is 80g/t ~ 320g/t.

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