Method for extracting molybdenum from low-grade single-molybdenum ore abandoned well stone

Abstract

The invention provides a method for extracting molybdenum from low-grade single-molybdenum ore abandoned well stone, and relates to the technical field of ore molybdenum extraction. According to the method, the single-molybdenum ore waste stone powder is subjected to low-temperature roasting by utilizing the fluidized bed, and the roasted ore powder is leached by combining with the active biological leaching liquid, so that the extraction rate of molybdenum is remarkably improved, and the molybdenum in the single-molybdenum ore is economically, safely and greenly extracted.

Description

TECHNICAL FIELD

[0001] The application provides a method for extracting molybdenum from low-grade single molybdenum ore abandoned well stone, and belongs to the technical field of ore molybdenum extraction. BACKGROUND

[0002] Low-grade single molybdenum ore is a kind of secondary oxide ore with a molybdenum content of 0.2-0.4%. The abandoned stone produced in the process of uranium mining in Zhangjiakou area of China is basically low-grade single molybdenum ore. The average content of molybdenum in single molybdenum ore abandoned stone is 0.25%. Molybdenum is an extremely important strategic metal, which is widely used in the manufacturing of advanced materials and products such as high-strength alloy steel, high-corrosion-resistant stainless steel, high-wear-resistant tool steel, high-temperature-resistant special steel, high-temperature alloy, catalyst, back electrode, heating body, lubricant, etc. It is related to many fields such as high-end manufacturing, aerospace, energy conversion, chemical industry, electronic information and national defense industry. Therefore, extracting and recovering molybdenum from single molybdenum ore abandoned stone not only has extremely high economic benefits but also has significant environmental and social benefits.

[0003] In recent years, many scholars have studied the separation, extraction and recovery process of valuable metal molybdenum in single molybdenum ore abandoned stone. Molybdenum in single molybdenum ore abandoned stone is mainly in the form of oxidized ore (more than 70%), combined with a large amount of mud ore, the traditional flotation process has the problems of high cost, low efficiency and high cost. The conventional sulfuric acid leaching process has a molybdenum dissolution rate of only about 30%, and low-temperature roasting at 400℃ for 1.5 hours can improve the acid dissolution efficiency of molybdenum to 60%. However, the traditional rotary kiln process has the problems of high energy consumption, long time, small processing capacity, large occupation area, high pretreatment cost and poor technical and economic performance for low-content single molybdenum ore abandoned stone. Therefore, it is necessary to develop a new single molybdenum ore abandoned stone molybdenum extraction technology with energy saving, low carbon and economy. SUMMARY

[0004] Therefore, the application provides a method for extracting molybdenum from low-grade single molybdenum ore abandoned well stone.

[0005] The application specifically realizes the following technical scheme: A method for extracting molybdenum from low-grade single molybdenum ore abandoned well stone, comprising the following steps: (1) crushing and grinding the single molybdenum ore abandoned stone to obtain a mineral powder; (2) low-temperature roasting the mineral powder by using a fluidized bed; (3) placing the roasted mineral powder in an active biological leaching solution and leaching under stirring to obtain a molybdenum-containing leaching solution; The active biological leaching solution contains the following components at the following concentrations: Fe 3+500-1000 mg / L, Fe 2+ 250-500 mg / L, amino acid 250-500 mg / L, extracellular polymers 250-500 mg / L.

[0006] Preferably, step (1) is to use an impact crusher to crush the single molybdenum ore waste into small pieces of centimeter scale, and after rough grinding and ball milling, a mineral powder with a particle size of 50-150 mesh is obtained.

[0007] Preferably, the parameters of the low-temperature roasting in step (2) are as follows: The air flow velocity of the fluidized bed nozzle is 20-100 m / s, the apparent gas flow velocity in the fluidized bed is 1.0-5.0 m / s, the roasting temperature is 350-400℃, and the roasting time is 10-25 minutes.

[0008] Preferably, the pH value of the active bioleaching solution in step (3) is 0.4-0.6.

[0009] Preferably, the solid-liquid ratio of the mineral powder and the active bioleaching solution in step (3) is 2-3g:5mL.

[0010] Preferably, the leaching temperature in step (3) is 50-80℃, and the leaching time is 24-48 hours.

[0011] Preferably, the stirring speed in step (3) is 30-60 revolutions per minute.

[0012] Compared with the prior art, the present application has the following beneficial effects: The present application uses a fluidized bed to perform low-temperature roasting on single molybdenum ore waste powder, and combines active bioleaching solution to leach the roasted mineral powder, thereby significantly improving the extraction rate of molybdenum and realizing economic, safe and green extraction of molybdenum in single molybdenum ore. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the present application clearer, the preferred embodiments of the present application will be further described in detail below in combination with examples. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application.

[0014] Example 1 Step 1. Breaking and grinding of single molybdenum ore waste. Use an impact crusher to crush the single molybdenum ore waste into small pieces of centimeter scale, and further grind the single molybdenum ore to a mineral powder with a particle size of 50 mesh by rough grinding and ball milling. Spray vaporized water mist to maintain an environment humidity of 60% during the grinding process to suppress dust.

[0015] Step 2. Fluidized bed low temperature roasting. The ore powder prepared in step 1 was input into a fluidized bed reactor for low temperature fluidized roasting. The air flow velocity of the fluidized bed nozzle was 40 m / s, the apparent gas flow velocity in the fluidized bed was 2.0 m / s, the roasting temperature was 350 °C, and the roasting (residence) time was 15 minutes. The high-temperature gas discharged was recycled to dry the single molybdenum ore powder and heat the air into the kiln.

[0016] Step 3. Molybdenum extraction using active bioleaching solution. The active bioleaching solution was prepared by using the active bioleachate generated by the oxidation of waste sulfur paste and pyrite by the sulfur / iron autotrophic bacterial community in the membrane bioreactor (MBR). The pH value of the active bioleaching solution was 0.5, the Fe 3+ concentration was 500 mg / L, the Fe 2+ concentration was 250 mg / L, the amino acid concentration was 250 mg / L, and the extracellular polymeric substance concentration was 300 mg / L. The low-temperature roasted ore powder was placed in the active bioleaching solution at a solid-liquid ratio of 2 g:5 mL, and leaching was carried out at a temperature of 70 °C and a stirring speed of 60 rpm for 48 hours to obtain a molybdenum-containing leaching solution. The molybdenum leaching rate of the single molybdenum ore was 65%, the molybdenum concentration of the leaching solution was 1000 mg / L, and the pH was 1.0.

[0017] Example 2 Step 1. Crushing and grinding of single molybdenum ore rejects. The single molybdenum ore rejects were crushed into small pieces of centimeter scale using an e-type crusher, and further ground by coarse grinding and ball grinding to obtain ore powder with a particle size of 100 mesh. Vaporized water mist was sprayed during the grinding process to maintain an environmental humidity of 90% to suppress dust.

[0018] Step 2. Fluidized bed low temperature roasting. The ore powder prepared in step 1 was input into a fluidized bed reactor for low temperature fluidized roasting. The air flow velocity of the fluidized bed nozzle was 40 m / s, the apparent gas flow velocity in the fluidized bed was 2.0 m / s, the roasting temperature was 350 °C, and the roasting (residence) time was 15 minutes. The high-temperature gas discharged was recycled to dry the single molybdenum ore powder and heat the air into the kiln.

[0019] Step 3. Molybdenum extraction using active bioleaching solution. The active bioleaching solution was prepared by using the active bioleachate generated by the oxidation of waste sulfur paste and pyrite by the sulfur / iron autotrophic bacterial community in the membrane bioreactor (MBR). The pH value of the active bioleaching solution was 0.5, the Fe 3+ concentration was 750 mg / L, the Fe 2+ concentration was 350 mg / L, the amino acid concentration was 400 mg / L, and the extracellular polymeric substance concentration was 500 mg / L. The low-temperature roasted ore powder was placed in the active bioleaching solution at a solid-liquid ratio of 2 g:5 mL, and leaching was carried out at a temperature of 80 °C and a stirring speed of 30 rpm for 48 hours to obtain a molybdenum-containing leaching solution. The molybdenum leaching rate of the single molybdenum ore was 75%, the molybdenum concentration of the leaching solution was 1200 mg / L, and the pH was 1.0.

[0020] Case 3 Step 1. Breaking and grinding of molybdenum ore rejects. The molybdenum ore rejects were broken into small pieces of centimeter scale using a jaw crusher, and further ground to a particle size of 150 mesh using a ball mill. The grinding process was carried out with a vaporized water spray to maintain the ambient humidity at 60% to suppress dust.

[0021] Step 2. Low temperature roasting in a fluidized bed. The ore powder prepared in Step 1 was fed into a fluidized bed reactor for low temperature fluidized roasting. The air flow velocity at the fluidized bed nozzle was 50 m / s, the superficial gas velocity in the fluidized bed was 2.5 m / s, the roasting temperature was 400°C, and the roasting (residence) time was 10 minutes. The high temperature gas discharged was recycled for drying the molybdenum ore powder and heating the air.

[0022] Step 3. Molybdenum extraction using active bioleach liquor. The active bioleach liquor generated by the oxidation of waste sulfur paste and pyrite by the sulfur / iron autotrophic bacterial community in the membrane bioreactor (MBR) was used as the active bioleach liquor, wherein the pH value of the active bioleach liquor was 0.6, the Fe 3+ concentration was 500 mg / L, the Fe 2+ concentration was 250 mg / L, the amino acid concentration was 250 mg / L, and the extracellular polymeric substance concentration was 250 mg / L. The low temperature roasted ore powder was placed in the active bioleach liquor at a solid-liquid ratio of 3 g:5 mL, and leached at a temperature of 50°C and a stirring speed of 60 rpm for 48 hours to obtain a molybdenum-containing leach liquor, wherein the molybdenum leaching rate of the molybdenum ore was 70%, the molybdenum concentration of the leach liquor was 900 mg / L, and the pH was 1.0.

[0023] The above-described embodiments are part of, but not all of, the embodiments of the present application. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but merely represents selected embodiments of the application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work, fall within the scope of protection of the present application.

Claims

1. A method for extracting molybdenum from abandoned rock in low-grade molybdenum ore mines, characterized in that, Includes the following steps: (1) The waste rock of single molybdenum ore is crushed and ground to obtain mineral powder; (2) The mineral powder is subjected to low-temperature roasting using a fluidized bed; (3) The roasted mineral powder is placed in an active biological leaching solution and leached under stirring to obtain a molybdenum-containing leaching solution; The active biological extract contains the following components at the following concentrations: Fe 3+ 500-1000 mg / L, Fe 2+ 250-500 mg / L, amino acids 250-500 mg / L, extracellular polymers 250-500 mg / L.

2. The method for extracting molybdenum from abandoned rock in low-grade molybdenum ore mines as described in claim 1, characterized in that, Step (1) involves using a jaw crusher to crush the single molybdenum ore waste into small pieces of centimeter size, which are then coarsely ground and ball-milled to obtain mineral powder with a particle size of 50-150 mesh.

3. The method for extracting molybdenum from abandoned rock in low-grade molybdenum ore mines as described in claim 1, characterized in that, The parameters for the low-temperature calcination in step (2) are as follows: The airflow velocity at the fluidized bed nozzle is 20-100 m / s, the apparent gas velocity inside the fluidized bed is 1.0-5.0 m / s, the calcination temperature is 350-400℃, and the calcination time is 10-25 minutes.

4. The method for extracting molybdenum from abandoned rock in low-grade molybdenum ore mines as described in claim 1, characterized in that, The pH value of the active biological extract in step (3) is 0.4-0.

6.

5. The method for extracting molybdenum from abandoned rock in a low-grade molybdenum mine as described in claim 1, characterized in that, The solid-liquid ratio of the mineral powder and the active biological immersion solution in step (3) is 2~3g:5mL.

6. The method for extracting molybdenum from abandoned rock in a low-grade molybdenum mine as described in claim 1, characterized in that, In step (3), the extraction temperature is 50-80℃ and the extraction time is 24-48 hours.

7. The method for extracting molybdenum from abandoned rock in a low-grade molybdenum mine as described in claim 1, characterized in that, In step (3), the stirring speed is 30-60 rpm.