A method for harmless secondary utilization of copper slag

Abstract

The present invention provides a method for harmless secondary utilization of matte slag, belonging to the field of comprehensive utilization of solid waste. The present invention first crushes the matte slag, then grinds it, and then magnetically separates it, and then separates the crude copper powder by gravity separation, and screens out copper concentrate from the crude copper powder and obtains high-grade copper concentrate by magnetic separation, and at the same time, the generated middlings are also magnetically separated to obtain low-grade crude copper powder. The present invention solves the problem that matte slag cannot be recycled, has a simple process and a compact structure, and all the unusable slags such as copper smelting slag and lead-zinc smelting slag that could not be normally utilized in the past are all recycled, generating huge economic benefits, truly realizing the transformation of waste into treasure, being pollution-free, environmentally friendly, and belonging to clean utilization.

Description

Technical Field

[0001] The invention relates to the field of comprehensive utilization of solid waste, and in particular to a method for harmless secondary utilization of matte slag. Background Art

[0002] Matte slag is the slag from the process of blowing matte into blister copper. In the process of blowing matte into blister copper, the non-copper elements in the matte are oxidized in sequence, some (such as sulfur) enter the flue gas, and some (such as iron, cobalt, and nickel) enter the slag. Elements that are less oxidizable than copper (such as precious metals) remain in the blister copper. Different elements will be enriched in the slag during different blowing periods. For example, the slag in the early stage of blowing mainly contains iron, and the slag in the later stage of blowing is enriched with cobalt and nickel. The terminal slag has a high copper content and is generally returned for use to recover copper. The early blowing slag contains 1-4% metallic copper, which is retained in the slag in the form of particles. The content of secondary copper sulfide and primary copper sulfide is extremely low, generally 0.099% and 0.005%, which have no recovery value. The iron content is about 35%. Due to cost considerations, it cannot be returned to copper smelting and can only be piled up for treatment.

[0003] At present, the main process for treating matte slag is direct leaching, which requires a large amount of ore to be processed, resulting in high leaching costs. The traditional treatment method not only pollutes the environment, occupies land resources, but also wastes precious copper resources. Summary of the invention

[0004] The purpose of the present invention is to provide a method for harmless secondary utilization of matte slag. The method provided by the present invention has no waste gas discharge and no waste water discharge throughout the whole process, and the tailings are put to valuable use.

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

[0006] The present invention provides a method for harmless secondary utilization of matte slag, comprising the following steps:

[0007] 1) crushing, grinding and first magnetic separation of matte slag in sequence to obtain iron ore concentrate and first tailings;

[0008] 2) performing a first gravity separation on the first tailings in step 1) to obtain crude copper powder, a first intermediate ore and a second tailings;

[0009] 3) subjecting the crude copper powder in step 2) to a second gravity separation to obtain copper concentrate, a second intermediate ore and a third tailings;

[0010] 4) subjecting the copper concentrate in step 3) to a second magnetic separation to obtain high-grade copper concentrate and iron concentrate;

[0011] 5) mixing the first intermediate ore in step 2) and the second intermediate ore in step 3) and performing a third magnetic separation to obtain low-grade crude copper powder and iron ore concentrate;

[0012] 6) The second tailings in step 2) and the third tailings in step 3) are dehydrated to obtain silicate ore powder and tail water, and the obtained tail water is filtered and then reused in the grinding process.

[0013] Preferably, the block diameter of the slag obtained after crushing in step 1) is 0.5-5 cm.

[0014] Preferably, the grinding in step 1) is grinding with water, and the mass of the added water is 2-3 times the mass of the matte slag.

[0015] Preferably, the particle size of the mineral powder in the ore slurry obtained after grinding in step 1) is -100 mesh.

[0016] Preferably, the magnetic field strength of the magnetic separation in step 1) is 250-350 MT.

[0017] Preferably, the first gravity separation in step 2) is centrifugal gravity separation.

[0018] Preferably, the second gravity separation in step 3) is a shaking table gravity separation, and the copper content in the copper concentrate is 75% to 80%.

[0019] Preferably, the magnetic field intensity of the second magnetic separation in step 4) is 350-450 MT, the copper content of the high-grade copper concentrate is 90-95%, and the iron content of the iron concentrate is greater than 45%.

[0020] Preferably, the magnetic field intensity of the third magnetic separation in step 5) is 450-500 MT, the copper content in the low-grade crude copper powder is 45-55%, and the iron content in the iron concentrate is greater than 45%.

[0021] Preferably, the water content of the silicate mineral powder in step 6) is 10-13%.

[0022] Beneficial technical effects of the present invention:

[0023] The present invention sequentially crushes, grinds and performs the first magnetic separation of matte slag to obtain iron concentrate and the first tailings; the first tailings are subjected to the first gravity separation to obtain crude copper powder, the first intermediate ore and the second tailings; the crude copper powder is subjected to the second gravity separation to obtain copper concentrate, the second intermediate ore and the third tailings; the copper concentrate is subjected to the second magnetic separation to obtain high-grade copper concentrate and iron concentrate; the first intermediate ore and the second intermediate ore are mixed and subjected to the third magnetic separation to obtain low-grade crude copper powder and iron concentrate; the second tailings and the third tailings are subjected to dehydration treatment to obtain silicate ore powder and tail water, and the obtained tail water is filtered and reused in the grinding process. The present invention realizes the recycling of matte slag resources, alleviates the shortage pressure of iron resources and copper resources, has a simple operation process, a compact structure, no exhaust gas is emptied throughout the process, no waste water is discharged, and the problem of stacking and environmental pollution of solid waste tailings is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart for the harmless comprehensive utilization of matte slag. DETAILED DESCRIPTION

[0025] The present invention provides a method for harmless secondary utilization of matte slag, comprising the following steps:

[0026] 1) crushing, grinding and first magnetic separation of matte slag in sequence to obtain iron ore concentrate and first tailings;

[0027] 2) performing a first gravity separation on the first tailings in step 1) to obtain crude copper powder, a first intermediate ore and a second tailings;

[0028] 3) subjecting the crude copper powder in step 2) to a second gravity separation to obtain copper concentrate, a second intermediate ore and a third tailings;

[0029] 4) subjecting the copper concentrate in step 3) to a second magnetic separation to obtain high-grade copper concentrate and iron concentrate;

[0030] 5) subjecting the first intermediate ore in step 2) and the second intermediate ore in step 3) to a third magnetic separation to obtain low-grade crude copper powder and iron ore concentrate;

[0031] 6) The second tailings in step 2) and the third tailings in step 3) are dehydrated to obtain silicate ore powder and tail water, and the obtained tail water is filtered and then reused in the grinding process.

[0032] The present invention crushes, grinds and performs the first magnetic separation on matte slag in sequence to obtain iron concentrate and the first tailings.

[0033] In the present invention, the crushing is preferably performed by coarse crushing first and then fine crushing. The block diameter of the material obtained after the coarse crushing is preferably 10-20 cm, more preferably 14-16 cm; the coarse crushing is preferably performed in a jaw crusher; the block diameter of the material obtained after the fine crushing is preferably 0.5-5 cm, more preferably 1-2 cm; the fine crushing is preferably performed in a hammer crusher.

[0034] In the present invention, the grinding is preferably grinding with water; the mass of the added water is preferably 2-3 times the mass of the matte slag, more preferably 2 times; the grinding time is preferably 10-20 minutes, more preferably 15 minutes, and the grinding particle size is preferably -100 mesh.

[0035] In the present invention, the magnetic field strength of the first magnetic separation is preferably 250-350 MT, more preferably 300 MT.

[0036] In the present invention, the iron content of the iron ore concentrate is greater than 45%. The iron ore concentrate of the present invention is used for ore blending or sponge iron production.

[0037] The invention reduces energy consumption by coarsely crushing the matte slag, then finely crushing it, and then adding water to grind it, and screens out iron concentrate containing more than 45% of iron through the first magnetic separation.

[0038] After obtaining the iron ore concentrate and the first tailings, the present invention performs a first gravity separation on the first tailings to obtain crude copper powder, the first intermediate ore and the second tailings.

[0039] In the present invention, the first gravity separation is preferably centrifugal gravity separation, and the centrifugal gravity separation is preferably carried out in a centrifugal concentrator.

[0040] In the present invention, the copper content of the crude copper powder is 40-43%.

[0041] The present invention separates various mixed ore particles by gravity separation according to the difference in density or particle size, so that the mixed ore particles are separated in a moving medium due to different settling speeds and different degrees of movement.

[0042] After obtaining the crude copper powder and the second tailings, the present invention performs a second gravity separation on the crude copper powder to obtain copper concentrate, the second intermediate ore and the third tailings.

[0043] In the present invention, the second gravity separation is preferably a shaking table gravity separation; the copper content in the copper concentrate is 75% to 80%.

[0044] After obtaining the second intermediate ore and the third tailings of the copper concentrate, the present invention performs a second magnetic separation on the copper concentrate to obtain high-grade copper concentrate and iron concentrate.

[0045] In the present invention, the magnetic field strength of the second magnetic separation is preferably 350-450 MT, more preferably 400 MT.

[0046] In the present invention, the copper content of the high-grade copper concentrate is 90-95%; the iron content of the iron concentrate is 45-47%. The copper concentrate and low-grade crude copper powder of the present invention are good raw materials for crude copper production, and the iron concentrate is added to the high-grade iron powder for sintering iron or making sponge iron raw materials.

[0047] The present invention mixes the first intermediate ore and the second intermediate ore to carry out the third magnetic separation to obtain crude copper powder and iron concentrate.

[0048] In the present invention, the magnetic field strength of the third magnetic separation is preferably 450-500 MT, more preferably 500 MT.

[0049] In the present invention, the copper content in the low-grade crude copper powder is 45-55%, and the iron content in the iron concentrate is greater than 45%.

[0050] In the present invention, the moisture content of the high-grade copper concentrate and the low-grade crude copper powder is preferably 10-13%. 。

[0051] The invention separates the ore particles into layers according to specific gravity and particle size under the action of gravity, horizontal water impact, inertia and friction generated by the reciprocating asymmetric motion of the bed surface, selects copper concentrate with a larger specific gravity from the crude copper powder through a shaking table device, obtains high-grade copper concentrate and iron concentrate again after magnetic separation; even if the crude copper powder still contains high levels of metallic copper and iron after screening, magnetic separation is performed to obtain iron concentrate and crude copper powder, and the crude copper powder is separated into tailings according to actual conditions.

[0052] In the present invention, the second tailings and the third tailings are subjected to dehydration treatment to obtain silicate ore powder and tail water, and the obtained tail water is filtered and then reused and ground.

[0053] In the present invention, the water content of the silicate mineral powder is 10-13%.

[0054] In the present invention, the tail water is filtered and reused.

[0055] The silicate mineral powder in the present invention is used as raw material for producing cement; the tail water enters the reservoir, and because the water is filtered by a filter, it has less impurities and fully meets the standards for medium water, can be recycled, and is not discharged.

[0056] The present invention reuses all the copper smelting slag and copper-lead-zinc smelting slag and other unusable slags that could not be normally utilized in the past, generates huge economic benefits, truly realizes the transformation of waste into treasure, is pollution-free, environmentally friendly, and belongs to clean utilization.

[0057] Example 1

[0058] 1) The matte slag used is the matte slag of Guotou Jincheng Metallurgical Co., Ltd., with a metallic copper content of 5% and a total iron content of 41.7%. The slag exists in a flaky structure, and the metallic copper is embedded in it in different granular forms. 500 kg of the matte slag is randomly taken, and is coarsely crushed to a block size of 14-16 cm by a 400*600 jaw crusher, and then sent to a hammer crusher with a block size of 1-2 cm by a feeder, and then sent to a grid ball mill through a vibrating feeder, 1500 kg of water is added, and ball milling is carried out for 15 minutes until the fineness of -100 mesh is fully passed, and the slurry enters a semi-countercurrent magnetic separator through gravity flow for magnetic separation at a magnetic field strength of 300 MT to obtain iron ore concentrate and the first tailings.

[0059] 2) The first tailings flow into the ore pool and are pumped into the centrifugal concentrator through a slurry pump for gravity separation to separate the crude copper powder, centrifugal middlings and the second tailings. The crude copper powder is put into the concentrate pool for standby use, the centrifugal middlings flow into the middling pool, and the second tailings enter the tailings pipeline.

[0060] 3) The crude copper powder is sent to the gravity separation shaking table to select copper concentrate, shaking table middlings and the third tailings. The copper concentrate is sent to the drum magnetic separator through the slag pump, and magnetic separation is carried out under the magnetic field intensity of 400MT to produce high-grade copper concentrate and iron concentrate; the shaking table middlings flow into the middling pool, and the third tailings enter the tailings pipeline.

[0061] 4) The centrifugal middlings in the middling pool and the shaking table middlings are sent to the drum magnetic separator through a slag pump, and magnetically separated at a magnetic field strength of 500 MT to produce low-grade crude copper powder and iron concentrate.

[0062] 5) Dehydrate the high-grade copper concentrate, low-grade crude copper powder and iron concentrate by filter pressing until the moisture content is 13% ；

[0063] 6) The second tailings and the third tailings are dehydrated to a moisture content of 12% to obtain silicate ore powder and collect tail water. The silicate ore powder is used to prepare cement, and the tail water is filtered and reused.

[0064] According to the testing of SDIC Jincheng Metallurgical, the copper content of the obtained high-grade copper concentrate was 94.25%, the copper content of the low-grade crude copper powder was 49.48%, the total iron content of the iron concentrate was 46.79%, and the copper content of the tailings was 0.02%.

[0065] Example 2

[0066] 1) The matte slag used is the copper smelting slag from Yunnan Honghe Prefecture, with a metallic copper content of 3% and a total iron content of 37%. 300 kg of the matte slag is randomly taken, and is roughly crushed to a block size of 10-20 cm by a 400600 jaw crusher, and then sent to a hammer crusher with a block size of 0.5-5 cm by a feeder, and then sent to a grid ball mill by a vibrating feeder, 1000 kg of water is added, and ball milled for 20 minutes until the fineness of -100 mesh is fully passed, and the slurry enters a semi-countercurrent magnetic separator by gravity for magnetic separation at a magnetic field strength of 350 MT to obtain iron ore concentrate and a first tailing;

[0067] 2) The first tailings flow into the ore pool, and are pumped into the centrifugal concentrator through a slurry pump for gravity separation, and crude copper powder, centrifugal middlings and second tailings are separated. The crude copper powder is reserved, the centrifugal middlings flow into the middling pool, and the second tailings enter the tailings pipeline;

[0068] 3) The crude copper powder is sent to the gravity separation shaking table to select copper concentrate, shaking table middlings and the third tailings. The copper concentrate is sent to the drum magnetic separator through the slag pump, and magnetic separation is carried out under the magnetic field intensity of 450MT to produce high-grade copper concentrate and iron concentrate; the shaking table middlings flow into the middling pool; the third tailings enter the tailings pipeline.

[0069] 4) The centrifugal middlings and shaking table middlings in the middling pool are sent to the drum magnetic separator through a slag pump for magnetic separation at a magnetic field strength of 450 MT to produce low-grade crude copper powder and iron ore concentrate;

[0070] 5) Dehydrate the high-grade copper concentrate, low-grade crude copper powder and iron concentrate by filter pressing until the moisture content is 10%

[0071] 6) The second tailings and the fourth tailings are dehydrated to a moisture content of 10% to obtain silicate ore powder and collect tail water. The silicate ore powder is used to prepare cement, and the tail water is filtered and reused.

[0072] According to the test results of the laboratory of Shanxi Provincial Bureau of Geology and Mineral Resources, the copper content of the high-grade copper concentrate is 89.16%, the copper content of the low-grade crude copper powder is 42.34%, the total iron content of the iron concentrate is 41.23%, and the copper content of the tailings is 0.03%.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for harmless secondary utilization of matte slag, characterized in that: The following steps are involved: 1) crushing, grinding and first magnetic separation of matte slag in sequence to obtain iron ore concentrate and first tailings; 2) performing a first gravity separation on the first tailings in step 1) to obtain crude copper powder, a first intermediate ore and a second tailings; 3) subjecting the crude copper powder in step 2) to a second gravity separation to obtain copper concentrate, a second intermediate ore and a third tailings; 4) subjecting the copper concentrate in step 3) to a second magnetic separation to obtain high-grade copper concentrate and iron concentrate; 5) mixing the first intermediate ore in step 2) and the second intermediate ore in step 3) and performing a third magnetic separation to obtain low-grade crude copper powder and iron ore concentrate; 6) The second tailings in step 2) and the third tailings in step 3) are dehydrated to obtain silicate ore powder and tail water, and the obtained tail water is filtered and reused in the grinding process.

2. The method according to claim 1, characterized in that The block diameter of the slag obtained after crushing in the step 1) is 0.5-5 cm.

3. The method according to claim 1, characterized in that The grinding in step 1) is grinding with water, and the mass of the added water is 2-3 times the mass of the matte slag.

4. The method according to claim 1 or 3, characterized in that: The particle size of the mineral powder in the ore slurry obtained after grinding in the step 1) is -100 mesh.

5. The method according to claim 1, characterized in that: The magnetic field strength of the magnetic separation in step 1) is 250-350 MT.

6. The method according to claim 1, characterized in that The first gravity separation in step 2) is centrifugal gravity separation.

7. The method according to claim 1, characterized in that The second gravity separation in step 3) is a shaking table gravity separation, and the copper content in the copper concentrate is 75% to 80%.

8. The method according to claim 1, characterized in that The magnetic field intensity of the second magnetic separation in step 4) is 350-450 MT, the copper content of the high-grade copper concentrate is 90-95%, and the iron content of the iron concentrate is greater than 45%.

9. The method according to claim 1, characterized in that: The magnetic field intensity of the third magnetic separation in step 5) is 450-500 MT, the copper content in the low-grade crude copper powder is 45-55%, and the iron content in the iron concentrate is greater than 45%.

10. The method according to claim 1, characterized in that The water content of the silicate mineral powder in step 6) is 10-13%.

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