Method for preparing steel slag micropowder from copper tailings

Abstract

The invention discloses a method for preparing steel slag micro-powder by using copper tailings, which comprises the following steps: scientifically mixing the copper tailings with a reducing agent, carrying out kiln roasting, magnetic separation and flotation by adopting a pyrogenic process, separating and recycling iron, zinc, copper and the like, drying the floated material, and carrying out ball milling treatment, thereby obtaining the steel slag micro-powder. The high-quality steel slag micro powder can be directly applied to building materials. According to the method, high-economic-benefit recovery treatment of the copper tailings can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of comprehensive utilization of copper tailings, and in particular to a method for preparing steel slag powder by utilizing copper tailings. Background Art

[0002] Copper tailings are the slag remaining after sintering and flotation at copper smelters. They are primarily composed of the residue left after ore is crushed, sintered, flotated, and then refined. They contain valuable mineral elements such as iron, zinc, and copper, as well as less useful minerals such as silicates. If used directly in building materials, copper tailings react with environmental substances, causing expansion and cracking in structures, as well as transport problems. However, long-term storage of copper tailings occupies significant land, generates dust and water pollution, and poses numerous safety risks. Summary of the Invention

[0003] Therefore, based on the above background, the present invention has developed a method for preparing steel slag powder using copper tailings. By fully recovering the valuable metal elements in the copper tailings, not only can iron concentrate, zinc concentrate, copper concentrate, etc. be obtained, but also high-quality steel slag powder that can be directly used in construction can be prepared.

[0004] The technical solution provided by the present invention is:

[0005] A method for preparing steel slag powder using copper tailings comprises the following steps:

[0006] 1) stirring and mixing the copper tailings, additives and activators to obtain a pre-treated material;

[0007] 2) calcining the pretreated material from step 1) in a rotary kiln, and collecting and cooling the rotary kiln dust using a dust collecting device;

[0008] 3) subjecting the calcined material to rapid cooling;

[0009] 4) Grinding the water-quenched material and then classifying it;

[0010] 5) The classified materials are subjected to magnetic separation, and the material obtained by magnetic separation is iron ore concentrate;

[0011] The dust collected by the dust collecting device after cooling is ball-milled to obtain zinc concentrate;

[0012] 6) The material after magnetic separation in step 5) is subjected to flotation to obtain copper powder. The flotation material is heated and dried, ball-milled, and then classified to prepare steel slag powder.

[0013] Furthermore, during the calcination in step 2), the temperature inside the rotary kiln is 900-1100° C. Furthermore, during the calcination in step 2), the calcination time in the rotary kiln is 70 minutes.

[0014] Furthermore, the weight ratio of the copper tailings to the additive is 1:0.28.

[0015] The weight ratio of the copper tailings to the activator is 1:(0.1-0.3)

[0016] Furthermore, the drying temperature in step 6) is controlled at 200°C.

[0017] Furthermore, the rapid cooling treatment in step 3) adopts water quenching.

[0018] The above technical solution has the following beneficial effects:

[0019] The present invention scientifically mixes copper tailings with a reducing agent and an additive, uses a pyrometallurgical method to efficiently reduce the hard-to-separate iron in the form of silicates, and then recovers it through ball milling and magnetic separation to produce iron concentrate, with a recovery rate of over 80%. Furthermore, by utilizing the high-temperature sublimation characteristics of zinc, zinc concentrate is produced through dust collection and cooling, with a recovery rate of over 90%. Furthermore, copper concentrate is produced through flotation recovery, with a recovery rate of over 80%.

[0020] After the copper tailings are used to recover iron, zinc and copper, the materials are dried and ball-milled to produce high-quality steel slag powder, which can be directly used in building materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attachment Figure 1 It is a broad spectrum analysis diagram of the copper tailings in the embodiment. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the implementation cases of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0023] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "vertical", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] In the description of the present invention, references to "first feature" and "second feature" may include one or more of these features. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features being described. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of these features.

[0025] The technical solution of the present invention is as follows:

[0026] A method for preparing steel slag powder using copper tailings comprises the following steps:

[0027] 1) stirring and mixing the copper tailings, additives and activators to obtain a pre-treated material;

[0028] The reducing agent includes coking coal, sodium chloride, calcium hydroxide and adhesive, which are configured in proportion, and the reducing agent is configured with the raw materials in a ratio of 1: (0.28-0.3), stirred evenly, and then pressed into balls.

[0029] The main purpose of the additive is to increase the activity index of steel slag powder. During the test, the activity index of the raw material was 70% after 28 days. To meet the standard, some materials that enhance the activity index must be added. Specifically, alkaline activators can be used, and steel slag and sulfate activators can also be used as activators.

[0030] 2) calcining the pretreated material from step 1) in a rotary kiln, and collecting and cooling the rotary kiln dust using a dust collecting device;

[0031] During calcination in this step, the temperature inside the rotary kiln is 900-1100°C. The temperature in this range can ensure sufficient recovery of zinc and also ensure the reduction standard of iron.

[0032] The calcination time is controlled at 70 minutes. This time is the ideal time obtained through repeated experiments. If the time is too short, the sintering will not be thorough, which will affect the reduction effect and the recovery rate. If the sintering time is too long, agglomeration or burning flow will occur, which will not achieve the reduction effect and will increase the mineral processing cost.

[0033] 3) Rapidly cool the calcined material to about 20 degrees;

[0034] The rapid cooling treatment in this step adopts water quenching to prevent the high-temperature reduced iron from being oxidized in the air.

[0035] 4) Grind the water-quenched material and then classify it; the water-quenched material is the reduced material, and the grinding and classification is mainly to separate the iron powder and impurities, and after separation, it is convenient to use a magnetic separator to recover the iron concentrate.

[0036] 5) The classified materials are subjected to magnetic separation, and the material obtained by magnetic separation is iron ore concentrate; the particle size of the iron ore concentrate is 200 mesh.

[0037] Purity i.e. grade 65%;

[0038] The dust collected by the dust collector is then ball-milled to obtain 50% zinc concentrate; zinc concentrate above 50% refers to the content. The zinc concentrate recovered by the pyrometallurgical method does not contain other metal elements.

[0039] 6) The material after magnetic separation in step 5) is subjected to flotation to obtain copper powder. The flotation material is heated and dried, ball-milled, and then classified to prepare steel slag powder.

[0040] Flotation is a process for mineral processing using a flotation machine. The main working principle is: copper and impurities are disintegrated through grinding, copper ions are captured by a collector and floated by a No. 2 oil frother, and copper concentrate is recovered by a scraper to obtain copper concentrate. Commonly used copper separation agents include No. 2 oil, xanthate, chlorinated water, glass water, and sodium chloride.

[0041] Copper concentrate with a grade of 20% refers to a content of 20%, which is the medium quality of copper concentrate purchased on the market.

[0042] The final steel slag micropowder products produced are of three grades: S75, S95 and S105. The higher the grade, the higher the market price. The product can be adjusted according to market demand, with high output and low production cost.

[0043] The drying temperature in this step is controlled at 200°C.

[0044] The present invention and its embodiments are described above. This description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs structures and embodiments similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing steel slag powder using copper tailings, characterized in that: The steps include: 1) stirring and mixing the copper tailings, additives and activators to obtain a pre-treated material; 2) calcining the pretreated material from step 1) in a rotary kiln, and collecting and cooling the rotary kiln dust using a dust collecting device; 3) subjecting the calcined material to rapid cooling; 4) Grinding the water-quenched material and then classifying it; 5) The classified materials are subjected to magnetic separation, and the material obtained by magnetic separation is iron ore concentrate; 6) The material after magnetic separation in step 5) is subjected to flotation to obtain copper powder. The flotation material is heated and dried, ball-milled, and then classified to prepare steel slag powder.

2. The method for preparing steel slag powder using copper tailings according to claim 1, characterized in that: During the calcination in step 2), the temperature inside the rotary kiln is 900-1100°C.

3. The method for preparing steel slag powder using copper tailings according to claim 2, characterized in that: The calcination time in the rotary kiln in step 2) is 70 minutes.

4. The method for preparing steel slag powder using copper tailings according to claim 1, characterized in that: The weight ratio of the copper tailings to the additive is 1:0.

28.

5. The method for preparing steel slag powder by utilizing copper tailings according to claim 4, characterized in that: The weight ratio of the copper tailings to the activator is 1:(0.1-0.3).

6. The method for preparing steel slag powder using copper tailings according to claim 1, characterized in that: The drying temperature in step 6) is controlled at 200°C.

7. The method for preparing steel slag powder using copper tailings according to claim 1, characterized in that: The rapid cooling treatment in step 3) adopts water quenching.

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