Advanced tailing discarding-ore phase conversion-magnetic separation deep impurity removal process for rhodochrosite

Abstract

The invention discloses a technology for preliminary tailing discarding of rhodochrosite, ore phase conversion and magnetic separation deep impurity removal, and belongs to the technical field of mineral processing. According to the method, ore with high calcium and magnesium content is removed in advance through an X-ray separation technology, then powder preparation and first-stage magnetic separation are carried out, the obtained first-stage magnetic separation manganese concentrate is fed into a suspension roaster, is in a suspension flow state in a nitrogen atmosphere and is subjected to a decomposition reaction to generate faux manganese ore (MnO) with the magnetism higher than that of rhodochrosite (MnCO3), and the faux manganese ore (MnO) is obtained. MnO with relatively high magnetism and non-magnetic calcium and magnesium impurities are more effectively separated through two-stage magnetic separation, and the grade of manganese concentrate is improved. According to the method, high-calcium and high-magnesium rhodochrosite is efficiently and comprehensively utilized, the technological process is simple, the heat and mass transfer efficiency is high, the reaction effect is good, the production continuity is good, the manganese grade and the manganese recovery rate in the product are high, and the calcium and magnesium removal effect is remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing and relates to a process for pre-discarding tailings of rhodochrosite-ore phase conversion-magnetic separation and deep impurity removal. Background Art

[0002] Manganese is irreplaceable in the production process of high-performance and high-quality steel materials. About 90% of manganese is used in the steel industry, second only to iron. At the same time, manganese is widely used in the electronics industry, chemical industry, aerospace industry and medical industry, especially in many strategic emerging industries today, such as advanced energy storage materials, battery materials, magnetic functional materials, etc.

[0003] At present, the commonly used rhodochrosite treatment methods are direct leaching (CN106745290A), roasting-leaching (CN116926347A), etc. However, impurities such as calcium and magnesium will form a passivation layer during the leaching process, affecting the leaching efficiency. Therefore, it is of great significance to develop a deep impurity removal process for rhodochrosite. In view of the above situation, the present invention provides a deep impurity removal process for rhodochrosite by pre-tailing-ore phase conversion-magnetic separation. Summary of the invention

[0004] The primary purpose of the present invention is to provide a method for pre-deep impurity removal of rhodochrosite, aiming to improve the leaching rate of manganese in subsequent leaching operations of rhodochrosite, and ultimately produce high-quality manganese concentrate.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A rhodochrosite pre-tailings-ore phase conversion-magnetic separation deep impurity removal process, comprising the steps of crushing the rhodochrosite and then performing pre-selection, grinding the obtained pre-selected concentrate and then performing a first-stage magnetic separation operation to obtain a first-stage magnetic separation manganese concentrate and a first-stage magnetic separation tailings; the first-stage magnetic separation manganese concentrate undergoes ore phase conversion in a suspension roaster, and the obtained ore phase conversion product undergoes a second-stage magnetic separation to obtain a second-stage magnetic separation concentrate and a second-stage magnetic separation tailings; the pre-selected tailings, the first-stage magnetic separation tailings and the second-stage magnetic separation tailings are combined into a total tailings, and the second-stage magnetic separation concentrate is the final product.

[0007] Crushing the rhodochrosite to a particle size of ≤130 mm;

[0008] Pre-selection is achieved by using X-ray intelligent sorting machine;

[0009] The pre-selected concentrate is crushed to a particle size of ≤0.15mm and then fed into the silo, of which -0.074mm ore powder accounts for ≥60% of the total mass;

[0010] The chemical composition of the rhodochrosite includes: Mn 22.00wt% to 33.50wt%, MgO 3.00wt% to 10.00wt%, and CaO 4.00wt% to 12.00wt%.

[0011] The magnetic field strength of the first stage magnetic separation is 12000Oe~16000Oe.

[0012] During the mineral phase transformation process, the roasting temperature is 500°C to 700°C; the roasting time is 15min to 30min; and nitrogen is used as the protective gas during the mineral phase transformation process.

[0013] The main chemical reactions occurring during the mineral phase transformation are:

[0014] The magnetic field strength during the second stage magnetic separation process is 2000Oe~7000Oe.

[0015] In the method, the magnesium ion removal rate is above 75%, and the calcium ion removal rate is above 73%.

[0016] The present invention provides a kind of rhodochrosite pre-tailing-ore phase conversion-magnetic separation deep impurity removal process, and its principle and technical key points are: due to the high content of impurities such as calcium and magnesium in rhodochrosite, these impurities are easy to form a passivation layer during the leaching process, which seriously affects the leaching efficiency. The present invention removes the ore with high calcium and magnesium content in advance by X-ray sorting technology, thereby improving the subsequent leaching efficiency. During the roasting process, the pre-selected rhodochrosite (MnCO3) is in a suspended fluid state under a nitrogen atmosphere, and a decomposition reaction occurs to generate schistosity (MnO) with stronger magnetism than rhodochrosite (MnCO3), which helps to more effectively separate the relatively strong magnetic MnO and non-magnetic calcium and magnesium impurities through magnetic separation, and improve the grade of manganese concentrate. In addition, rhodochrosite (MnCO3) belongs to the trigonal system, while schistosity (MnO) belongs to the cubic system. During the crystal structure transformation process, a large number of pores and microcracks are formed in the ore particles, which converts the originally dense mineral into a loose and porous structure, providing favorable conditions for subsequent leaching operations.

[0017] Compared with the existing electrolytic manganese waste slag treatment process, the characteristics and advantages of the present invention are:

[0018] 1. The present invention realizes the efficient comprehensive utilization of high-calcium and high-magnesium rhodochrosite, the manganese grade and manganese recovery rate in the product are high, and the calcium and magnesium removal effects are remarkable.

[0019] 2. The mineral phase transformation process of the present invention adopts a suspension roasting furnace to roast the rhodochrosite ore powder. Compared with the traditional roasting device rotary kiln, it has higher heat and mass transfer efficiency, better reaction effect and good production continuity.

[0020] 3. The process flow of pre-tailings of rhodochrosite - ore phase conversion - deep impurity removal by magnetic separation proposed in the present invention is simple, and the related technology is relatively mature, which is convenient for industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1The present invention is a schematic flow chart of the method for pre-discarding tailings of rhodochrosite - ore phase conversion - magnetic separation for deep impurity removal. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and examples. The test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described can be obtained from commercial channels unless otherwise specified, and the preferred embodiments described are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0023] Embodiment 1:

[0024] The rhodochrosite in this embodiment comes from the Akto-Wuqia area of ​​Xinjiang, wherein the Mn content, the MgO content, and the CaO content are 29.82wt%, 5.14wt%, and 6.64wt%.

[0025] This embodiment provides a method for pre-discarding tailings of rhodochrosite - ore phase conversion - magnetic separation deep impurity removal, the process flow is as follows Figure 1 As shown,

[0026] The rhodochrosite is fed into a coarse crusher for crushing to obtain a crushed product with a particle size of less than 90 mm. The crushed product is transported to the X-ray intelligent sorting equipment through a conveyor for pre-selection to obtain X-ray intelligent pre-selected concentrate and pre-selected tailings. The X-ray pre-selected concentrate is crushed to a particle size of less than 0.15 mm, of which -0.074 mm ore powder accounts for 60% of the total mass. The crushed sample is sent to a vertical ring high-intensity magnetic separator with a magnetic field strength of 12000Oe to obtain a first-stage magnetic separation concentrate and a first-stage magnetic separation tailings. After the first-stage magnetic separation product is dried in a dryer, it is sent to a suspension roaster with preheated nitrogen for mineral phase transformation, and the temperature in the suspension roaster is stabilized at 500°C. The roasting time is 15min, and finally a synergistic mineral phase transformation product is obtained. The material discharged from the suspension roaster is cooled by a cooling cyclone and fed into a second-stage magnetic separation with a magnetic field strength of 3000Oe to obtain a second-stage magnetic separation concentrate and a second-stage magnetic separation tailings. The second-stage magnetic separation concentrate in this embodiment is the final concentrate, and the X-ray intelligent pre-selection tailings, the first-stage magnetic separation tailings and the second-stage magnetic separation tailings are combined into the final tailings. The manganese grade of the final concentrate is 39.78wt%; the MgO content is 3.77wt%; and the CaO content is 3.21wt%. The manganese recovery rate is 85.92%, and the magnesium removal rate and calcium removal rate are 75.31% and 74.84% respectively.

[0027] Embodiment 2:

[0028] The method is the same as the method of pre-discarding tailings of rhodochrosite - ore phase conversion - magnetic separation deep impurity removal in Example 1, except that:

[0029] 1. The rhodochrosite in this embodiment has a Mn content of 29.97 wt%, a MgO content of 6.25 wt%, and a CaO content of 5.98 wt%.

[0030] 2. Grind the X-ray preselected concentrate to a particle size of less than 0.15 mm, of which -0.074 mm ore powder accounts for 60% of the total mass.

[0031] 3. The crushed samples are sent into a vertical ring high-intensity magnetic separator with a magnetic field strength of 13000Oe to obtain a section of magnetically separated concentrate and a section of magnetically separated tailings.

[0032] 4. After the first-stage magnetic separation product is dried in a dryer, it is sent into a suspension roasting furnace with preheated nitrogen for mineral phase transformation. The temperature in the suspension roasting furnace is stabilized at 550°C, and the roasting time is 15 minutes, and finally a synergistic mineral phase transformation product is obtained.

[0033] 5. The material discharged from the suspension roasting furnace is cooled by a cooling cyclone and then fed into a second-stage magnetic separation with a magnetic field strength of 2000Oe to obtain a second-stage magnetic separation concentrate and a second-stage magnetic separation tailings.

[0034] The second-stage magnetic separation concentrate in this embodiment is the final concentrate, and the X-ray pre-selection tailings, the first-stage magnetic separation tailings and the second-stage magnetic separation tailings are combined into the final tailings. The manganese grade of the manganese concentrate finally obtained is 40.57wt%; the MgO content is 3.41wt%; and the CaO content is 2.88wt%. The manganese recovery rate is 83.84%, and the magnesium removal rate and calcium removal rate are 76.77% and 74.81% respectively.

[0035] Embodiment 3:

[0036] The method is the same as the method of pre-discarding tailings of rhodochrosite - ore phase conversion - magnetic separation deep impurity removal in Example 1, except that:

[0037] 1. The Mn content of the rhodochrosite in this embodiment is 31.54wt%, the MgO content is 6.88wt%, and the CaO content is 6.14wt%.

[0038] 2. Grind the X-ray preselected concentrate to a particle size of less than 0.15 mm, of which -0.074 mm ore powder accounts for 70% of the total mass.

[0039] 3. The crushed samples are sent into a vertical ring high-intensity magnetic separator with a magnetic field strength of 2000Oe to obtain a section of magnetically separated concentrate and a section of magnetically separated tailings.

[0040] 4. After the first-stage magnetic separation product is dried in a dryer, it is sent to a suspension roasting furnace with preheated nitrogen for mineral phase transformation. The temperature in the suspension roasting furnace is stabilized at 600°C, and the roasting time is 20 minutes, and finally a synergistic mineral phase transformation product is obtained.

[0041] 5. The material discharged from the suspension roasting furnace is cooled by a cooling cyclone and then fed into a second-stage magnetic separation with a magnetic field strength of 3000Oe to obtain a second-stage magnetic separation concentrate and a second-stage magnetic separation tailings.

[0042] The second-stage magnetic separation concentrate in this embodiment is the final concentrate, and the X-ray pre-selection tailings, the first-stage magnetic separation tailings and the second-stage magnetic separation tailings are combined into the final tailings. The manganese grade of the manganese concentrate finally obtained is 41.10wt%; the MgO content is 3.78wt%; and the CaO content is 3.11wt%. The manganese recovery rate is 82.49%, and the magnesium removal rate and calcium removal rate are 78.17% and 75.28% respectively.

[0043] Embodiment 4:

[0044] The method is the same as the method of pre-discarding tailings of rhodochrosite - ore phase conversion - magnetic separation deep impurity removal in Example 1, except that:

[0045] 1. The Mn content of the rhodochrosite in this embodiment is 30.89wt%, the MgO content is 7.78wt%, and the CaO content is 6.91wt%.

[0046] 2. Grind the X-ray preselected concentrate to a particle size of less than 0.15 mm, of which -0.074 mm ore powder accounts for 75% of the total mass.

[0047] 3. The crushed samples are sent into a vertical ring high-intensity magnetic separator with a magnetic field strength of 13000Oe to obtain a section of magnetically separated concentrate and a section of magnetically separated tailings.

[0048] 4. After the first-stage magnetic separation product is dried in a dryer, it is sent to a suspension roasting furnace with preheated nitrogen for mineral phase transformation. The temperature in the suspension roasting furnace is stabilized at 700°C, and the roasting time is 25 minutes, and finally a synergistic mineral phase transformation product is obtained.

[0049] 5. The material discharged from the suspension roasting furnace is cooled by a cooling cyclone and then fed into a second-stage magnetic separation with a magnetic field strength of 4000Oe to obtain a second-stage magnetic separation concentrate and a second-stage magnetic separation tailings.

[0050] The second-stage magnetic separation concentrate in this embodiment is the final concentrate, and the X-ray pre-selection tailings, the first-stage magnetic separation tailings and the second-stage magnetic separation tailings are combined into the final tailings. The manganese grade of the manganese concentrate finally obtained is 39.78wt%; the MgO content is 2.88%; the CaO content is 2.15wt%. The manganese recovery rate is 77.83%, and the magnesium removal rate and calcium removal rate are 78.89% and 77.41% respectively.

[0051] Embodiment 5:

[0052] The method is the same as the method of pre-discarding tailings of rhodochrosite - ore phase conversion - magnetic separation deep impurity removal in Example 1, except that:

[0053] 1. The rhodochrosite in this embodiment comes from South Africa, wherein the Mn content is 23.78wt%, the MgO content is 4.73wt%, and the CaO content is 8.61wt%.

[0054] 2. Grind the X-ray preselected concentrate to a particle size of less than 0.15 mm, of which -0.074 mm ore powder accounts for 75% of the total mass.

[0055] 3. The crushed samples are sent into a vertical ring high-intensity magnetic separator with a magnetic field strength of 15000Oe to obtain a section of magnetically separated concentrate and a section of magnetically separated tailings.

[0056] 4. After the first-stage magnetic separation product is dried in a dryer, it is sent to a suspension roasting furnace with preheated nitrogen for mineral phase transformation. The temperature in the suspension roasting furnace is stabilized at 700°C, and the roasting time is 30 minutes, and finally a synergistic mineral phase transformation product is obtained.

[0057] 5. The material discharged from the suspension roasting furnace is cooled by a cooling cyclone and then fed into a second-stage magnetic separation with a magnetic field strength of 6000Oe to obtain a second-stage magnetic separation concentrate and a second-stage magnetic separation tailings.

[0058] The second-stage magnetic separation concentrate in this embodiment is the final concentrate, and the X-ray pre-selection tailings, the first-stage magnetic separation tailings and the second-stage magnetic separation tailings are combined into the final tailings. The manganese grade of the manganese concentrate finally obtained is 43.10wt%; the MgO content is 2.10wt%; the CaO content is 2.02wt%. The manganese recovery rate is 81.76%, and the magnesium removal rate and calcium removal rate are 77.99% and 73.23% respectively.

[0059] Embodiment 6:

[0060] The method is the same as the method of pre-discarding tailings of rhodochrosite - ore phase conversion - magnetic separation deep impurity removal in Example 1, except that:

[0061] 1. The rhodochrosite in this example comes from Guangxi Zhuang Autonomous Region, wherein the Mn content is 29.75wt%, the MgO content is 3.45wt%, and the CaO content is 11.53wt%.

[0062] 2. Grind the X-ray preselected concentrate to a particle size of less than 0.15 mm, of which -0.074 mm ore powder accounts for 80% of the total mass.

[0063] 3. The crushed samples are sent into a vertical ring high-intensity magnetic separator with a magnetic field strength of 15000Oe to obtain a section of magnetically separated concentrate and a section of magnetically separated tailings.

[0064] 4. After the first-stage magnetic separation product is dried in a dryer, it is sent to a suspension roasting furnace with preheated nitrogen for mineral phase transformation. The temperature in the suspension roasting furnace is stabilized at 700°C, and the roasting time is 30 minutes, and finally a synergistic mineral phase transformation product is obtained.

[0065] 5. The material discharged from the suspension roasting furnace is cooled by a cooling cyclone and then fed into a second-stage magnetic separation with a magnetic field strength of 7000Oe to obtain a second-stage magnetic separation concentrate and a second-stage magnetic separation tailings.

[0066] The second-stage magnetic separation concentrate in this embodiment is the final concentrate, and the X-ray pre-selection tailings, the first-stage magnetic separation tailings and the second-stage magnetic separation tailings are combined into the final tailings. The manganese grade of the manganese concentrate finally obtained is 43.21wt%; the MgO content is 2.57wt%; the CaO content is 1.80wt%. The manganese recovery rate is 80.12%, and the magnesium removal rate and calcium removal rate are 78.06% and 74.23% respectively.

Claims

1. A process for pre-disposal of rhodochrosite tailings - ore phase conversion - magnetic separation for deep impurity removal, characterized in that: The rhodochrosite is crushed and then pre-selected. The obtained pre-selected concentrate is crushed and ground and then subjected to a first-stage magnetic separation operation to obtain a first-stage magnetic separation manganese concentrate and a first-stage magnetic separation tailings; the first-stage magnetic separation manganese concentrate undergoes ore phase transformation in a suspension roaster, and the obtained ore phase transformation product is subjected to a second-stage magnetic separation to obtain a second-stage magnetic separation concentrate and a second-stage magnetic separation tailings; the pre-selected tailings, the first-stage magnetic separation tailings and the second-stage magnetic separation tailings are combined into a total tailings, and the second-stage magnetic separation concentrate is the final product.

2. A rhodochrosite pre-tailing-ore phase conversion-magnetic separation deep impurity removal process according to claim 1, characterized in that: The composition of rhodochrosite includes, by mass percentage: Mn 22.00wt% to 33.50wt%, MgO 3.00wt% to 10.00wt%, CaO 4.00wt% to 12.00wt%; The rhodochrosite is crushed to a particle size of ≤130 mm.

3. A rhodochrosite pre-tailing-ore phase conversion-magnetic separation deep impurity removal process according to claim 1, characterized in that: Pre-selection is achieved by using an X-ray intelligent sorting machine; the pre-selected concentrate is crushed to a particle size of ≤0.15mm and then fed into the silo, of which -0.074mm ore powder accounts for ≥60% of the total mass.

4. A rhodochrosite pre-tailing-ore phase conversion-magnetic separation deep impurity removal process according to claim 1, characterized in that: During a magnetic separation process, the magnetic field strength is 12000Oe~16000Oe.

5. A rhodochrosite pre-tailing-ore phase conversion-magnetic separation deep impurity removal process according to claim 1, characterized in that: During the mineral phase transformation process, the roasting temperature is 500°C to 700°C, and the mineral phase transformation time is 15min to 30min; nitrogen is used as the protective atmosphere during the mineral phase transformation process.

6. A rhodochrosite pre-tailing-ore phase conversion-magnetic separation deep impurity removal process according to claim 1, characterized in that: During the second stage magnetic separation process, the magnetic field strength is 2000Oe~7000Oe.

7. A rhodochrosite pre-tailing-ore phase conversion-magnetic separation deep impurity removal process according to claim 1, characterized in that: The pre-selected tailings, the first stage magnetic separation tailings and the second stage magnetic separation tailings are combined into the total tailings.

8. A rhodochrosite pre-tailings-ore phase conversion-magnetic separation deep impurity removal process according to any one of claims 1 to 7, characterized in that: The removal rate of magnesium ions in rhodochrosite is over 75%, and the removal rate of calcium ions is over 73%.

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