CN115430517A - Anshan type maghemite sectional grinding, heavy-magnetic process flow - Google Patents

Abstract

The invention discloses a process flow of sectionally grinding and gravity-magnetic grinding of raw ores, belonging to the technical field of ore dressing. Coarse crushing raw ore, operating by a semi-autogenous grinding-screening system, screening the obtained tailings by a weak magnetic machine, a strong magnetic machine and a primary ore grinding grading system, and then respectively removing the screened tailings; carrying out primary grinding classification system and secondary magnetic separation on the concentrate, classifying the obtained concentrate into coarse grit sand setting and fine overflow, and removing the obtained tailings; coarse-grained settled sand is separated by coarse-spiral and fine-spiral to obtain gravity concentrate and fine-spiral tailings, the coarse-spiral tailings and the fine-spiral tailings are mixed and subjected to secondary ore grinding and classification system operation, the mixture is subjected to fine-grained overflow mixing, and magnetic separation concentrate, three-magnetic separation tailings and four-magnetic separation tailings are obtained through three-magnetic separation and four-magnetic separation; and (4) removing tailings, and mixing the magnetic concentrate with the gravity concentrate to obtain concentrate with the grade of more than 65%. The invention cancels the flotation operation, reduces the use of medicaments, is beneficial to reducing the cost, has the flow comprising only heavy and magnetic processes, has relatively simple flow and is convenient to operate and control.

Description

An Anshan-style maghemite ore grinding, gravity-magnetic process flow

technical field

The invention belongs to the technical field of mineral processing, and in particular relates to an Anshan-type maghemite ore grinding and gravity-magnetic process flow.

Background technique

Anshan-type maghemite is an important type of iron ore in my country. At present, two production processes are mainly used: one is stage grinding, coarse and fine separation, gravity separation-strong magnetic field-anion reverse flotation process, see Figure 1. A grading overflow is divided into coarse and fine products through coarse and fine grading. The coarse-grained part is selected by coarse snail, fine snail, and snail-sweeping operations to select the gravity-separated concentrate, and the tailings are thrown away by weak and medium magnetic, and the medium ore is reground and returned to coarse and fine classification; the fine-grained part is thrown by medium and strong magnetic tailings. After being concentrated, it is fed into the reverse flotation operation, the flotation concentrate is selected, and the flotation tailings are thrown away. There are some deficiencies in the technological process: first, the tailing is not thrown early, and the process load is heavy; second, the process includes three kinds of heavy, magnetic and floating processes, and the process is relatively complicated; third, the large cycle of the medium mine may easily cause fluctuations in process indicators.

The second is continuous grinding (stage grinding), magnetic-flotation process. After the raw ore has been ground twice, the tailings are discarded by magnetic separation, the magnetic separation mixed concentrate is fed into flotation, the flotation concentrate is selected, and the flotation tailings are thrown away. The problem with this process is that the concentrate is a single flotation concentrate, and the consumption of flotation reagents is large and the cost is high.

The published patent 201510320314.4 fine-grain embedded mixed ore coarse-grain pre-selection and magnetic-gravity separation process adopts semi-self-grinding, wet pre-selection, continuous grinding, weak magnetic and strong magnetic, fine screen regrinding, and strong magnetic fine gravity separation process , there are the following problems: one is that the tailings of wet pre-selection are not recycled, and are directly discarded; The fine sieve regrinding process, the sieve returns to the secondary classification, the separation efficiency is low, and the large circulation of the medium ore is likely to cause fluctuations in process indicators.

Contents of the invention

In order to solve the problems existing in the prior art, in the existing low-grade Anshan-type maghemite process technology, the process load is large, there is no timely tailing and there is a long, complicated and difficult-to-control problem in the beneficiation process, the purpose of the present invention is to Provide an efficient, stable, and easy-to-control low-grade Anshan-style maghemite segmental grinding, gravity-magnetic process flow, improve the resource utilization effect of ore and the technical and economic indicators of mineral processing enterprises. By adding semi-autogenous grinding-screening system to throw away low-grade coarse tailings in time, reduce process load and reduce cost; at the same time, adopt primary grinding and grading system and secondary grinding and grading system to make most of the ore reach single solution It reduces the factors that cause process index fluctuations due to the large cycle of the medium mine; cancels the flotation operation, reduces the consumption of flotation chemicals, and reduces costs. The invention simplifies the sorting process, stabilizes the technical index and improves the sorting efficiency.

The purpose of the present invention is achieved through the following technical solutions:

A kind of Anshan type maghemite stage grinding, heavy-magnetic technological process, comprises the following steps:

(1) Anshan-type maghemite with a grade of 25-30% is roughly broken and then operated through a semi-autogenous grinding-screening system to obtain products with a particle size of 0-3mm, which are sorted by a weak magnetic machine and a strong magnetic machine in turn, The obtained concentrates are mixed and sent to the primary grinding and grading system, and the obtained tailings are screened and thrown away separately;

(2) Through the primary grinding and grading system until the overflow particle size reaches more than 60% of the -200 mesh content, the second magnetic separation operation is carried out, and the gained second magnetic separation concentrate is subjected to coarse and fine classification, and the gained second magnetic separation tailings are thrown away; the second magnetic separation After the magnetic separation concentrate is coarsely and subdivided, coarse-grained grit products and fine-grained overflow products are obtained. The coarse-grained grit products are sequentially sorted by coarse snails and fine snails to obtain re-separated concentrates with a grade of more than 65%. ore, coarse snail tailings, and fine snail tailings, and the coarse snail tailings and the fine snail tailings are mixed and fed into the secondary grinding and grading system;

(3) Through the secondary grinding and grading system until the overflow particle size reaches -325 mesh and the content is more than 90%, it is mixed with the fine-grained overflow product, and the magnetic separation with a grade of more than 65% is obtained through the third magnetic separation operation and the fourth magnetic separation operation Concentrate, and three magnetic separation tailings and four magnetic separation tailings; the third magnetic separation tailings and four magnetic separation tailings are thrown away, and the magnetic separation concentrate is mixed with the gravity separation concentrate to obtain grade 65 % above the concentrate.

Further, in the above technical solution, the Anshan-type maghemite with a grade of 25-30% may also be other maghemite with a grade of 25-30%.

Further, in the above technical solution, the Anshan-type maghemite is coarsely crushed to a particle size of less than 300mm; the described is sequentially separated by a weak magnetic machine and a strong magnetic machine, and the obtained concentrate is mixed and fed into a primary grinding and grading system. The obtained tailings are sieved and thrown away respectively, specifically including: sorting by a weak magnetic machine to obtain weak magnetic concentrate and weak magnetic tailings, and the weak magnetic tailings are sorted by a strong magnetic machine to obtain strong magnetic concentrate and Strong magnetic tailings, the weak magnetic concentrate and the strong magnetic concentrate are mixed and fed into a grinding and grading system; the strong magnetic tailings are screened to obtain coarse tailings products with a particle size of 0.3-3mm And fine-grained tailings with a particle size of 0-0.3mm.

Further, in the above technical solution, the grade of the strong magnetic tailings is less than 8%.

Further, in the above technical solution, the mixed grade of the weak magnetic concentrate and the strong magnetic concentrate is 35-45%.

Further, in the above technical scheme, the coarse-grained grit products are sequentially subjected to coarse snail separation and fine snail separation to obtain gravity-selected concentrate with a grade above 65%, coarse snail tailings, and fine snail tailings, specifically including : the coarse-grained grit products are sorted by coarse snails to obtain coarse snail concentrates and coarse snail tailings, and the coarse snail concentrates are separated by fine snails to obtain gravity-selected concentrates and refined snails with a grade of more than 65%. tailings.

Further, in the above technical solution, in step (2), the grade of the second magnetic separation concentrate is 45-55%, and the second magnetic separation tailings grade is less than 9%.

Further, in the above technical solution, the magnetic separation concentrate with a grade above 65% and the third magnetic separation tailings and the fourth magnetic separation tailings are obtained through the third magnetic separation operation and the fourth magnetic separation operation, specifically including: The magnetic separation operation obtains the third magnetic separation concentrate and the third magnetic separation tailings, and the third magnetic separation concentrate is fed into the fourth magnetic separation operation to obtain the magnetic separation concentrate and the fourth magnetic separation tailings with a grade above 65%.

Further, in the above technical solution, the grade of the coarse-grained tailings product is 7-14%.

Further, in the above technical solution, the coarse-grained sand settling product has a -200 mesh content of 30-50%, and the fine-grained overflow product has a -200 mesh content of more than 85%.

Further, in the above technical solution, the fine-grained tailings, the second magnetic separation tailings, the third magnetic separation tailings and the fourth magnetic separation tailings are mixed into tailings with a grade of 8-10%.

Further, in the above technical solution, the magnetic separator used in the four magnetic separation operations is an elutriation machine; the excitation current of the elutriation machine is above 1.0A.

Further, in the above technical solution, the field strength of the magnetic weakening machine is 0.15-0.2T; the field strength of the strong magnetic machine is above 1T; the field strength of the second magnetic separation is 0.4-0.6T; The field strength of the third magnetic separation is 0.2-0.4T.

Further, in the above technical solution, the grinding equipment of the semi-autogenous grinding-screening system includes a semi-autogenous mill, and the screening equipment includes a linear screen; the screening equipment for tailings in step (1) includes a dewatering screen; The grinding equipment of the primary grinding and grading system includes a ball mill; the grinding equipment of the secondary grinding and grading system includes a tower mill.

Further, in the above technical solution, the aperture of the dewatering screen is 0.3-0.5 mm.

Beneficial effects of the invention:

1) In the present invention, the 0-3mm product after closed-circuit semi-autogenous grinding-screening, the overflow product with a content of more than 60% of -200 mesh after the first grinding and classification, and the overflow product with a content of more than 90% of -325 mesh after the second grinding and classification After the product is magnetically separated, the tail is thrown, which meets the requirements of early throwing, reduces the follow-up work load, and reduces costs.

2) The present invention cancels the flotation operation, reduces the use of medicaments, and helps to reduce costs, and the process only includes gravity and magnetic processes, the process is relatively simple, easy to operate and control, and is conducive to process and index stability and cost reduction.

3) In the present invention, the coarse snail tailings and fine snail tailings are directly fed into the secondary grinding and grading system, so that the particle size of the overflow product is -325 mesh and the content is more than 90%, and most of the ore monomers are directly dissociated. The cancellation of the medium ore cycle is conducive to the stability of process indicators, and the coarse and fine grading overflow and the overflow products of the secondary grinding and grading system are sorted by high-efficiency magnetic separation equipment such as elutriation machines, which can improve the grade of magnetic separation concentrate.

4) The present invention screens the strong magnetic tailings to form coarse tailings products, which can be used as sand and gravel aggregates, concrete fine aggregates, railway ballast and cement raw materials, etc., which improves resource utilization.

Description of drawings

Fig. 1 is the traditional beneficiation process flow chart of maghemite in the prior art.

Fig. 2 is the ore dressing process flow chart of the present invention.

detailed description

The following non-limiting examples can enable those skilled in the art to understand the present invention more fully, but do not limit the present invention in any way.

Example 1

The embodiment of the present invention is taken from a maghemite ore in Anshan City.

As shown in Figure 2, a maghemite ore in Anshan City of the present invention is staged grinding, gravity-magnetic process flow, and a certain maghemite ore in Anshan City with a grade of 25% is fed into the sorting process of the present invention , to carry out subsequent grinding and sorting treatment, which specifically includes the following steps:

Step 1. A maghemite ore with a grade of 25% in Anshan City is coarsely crushed and put into a closed-circuit semi-autogenous grinding-screening operation, and the under-screened product (0-3mm) is fed into a magnetic weakening machine (field strength is 0.2T ), the strong magnetic machine operation (the field strength is 1.0T) carries out the coarse particle sorting, and the grade is 7.07%, and the strong magnetic tailings with yield rate 31.34% is given to the dewatering sieve for screening, and the sieve hole of the dewatering sieve is 0.3mm, and the sieve The upper product (0.3-3mm) is a coarse tailings product with a grade of 10.28% and a yield of 8.16%. The under-screen product (0-0.3mm) is a fine tailings with a grade of 5.94% and a yield of 23.18%. . The weak magnetic concentrate and strong magnetic concentrate are mixed into the primary grinding and grading system, and the overflow particle size reaches -200 mesh above 60%, and then fed into the second magnetic separation operation (field strength is 0.4T) for separation, and the discarded grade is 8.56%, the yield is 24.38% of the second magnetic separation tailings.

Step 2. Feed the secondary magnetic separation concentrate with a grade of 52.01% and a yield of 44.28% into the coarse and fine classification operation, and the coarse-grained grit products with a content of -200 mesh and 40% are selected by coarse and fine snails with a grade of 66.18 %, with a yield of 4.70%, the gravity separation concentrate, coarse snail tailings and fine snail tailings are mixed into the secondary closed-circuit grinding and grading system for operation, so that the secondary grading overflow particle size can reach -325 mesh 93%, and the grade is 50.33%, yield 39.58%.

Step 3, the grade is 50.33%, the yield rate is 39.58% secondary graded overflow and -200 mesh content 85% or more fine-grained overflow product mixed ore is fed into three magnetic separation operations (field strength is 0.4T), Four magnetic separation operations (excitation current is 1.0A, rising water flow size is 1.1×10 ³ L/h), the magnetic separation concentrate with a grade of 65.94% and a yield of 27.99% is selected, and the third magnetic ore with a grade of 12.18% is discarded Separation tailings and four magnetic separation tailings with a grade of 14.66%.

Step 4. Gravity separation concentrate and magnetic separation concentrate are combined into final concentrate with a grade of 65.97%; the grade of coarse tailings screened out by dehydration screen is 10.28%; fine tailings, second magnetic separation tailings, third The magnetic separation tailings and the four magnetic separation tailings are mixed into the final tailings with a grade of 8.56%.

Compared with stage grinding, coarse and fine separation, gravity separation-strong magnetic-anion reverse flotation process and continuous grinding (stage grinding) and magnetic-flotation process, the concentrate grade is basically the same, and the tailings are reduced by 1- 1.5%, 10-20% reduction in concentrate cost.

Example 2

The embodiment of the present invention is taken from a maghemite ore in Luan County.

As shown in Figure 2, a certain maghemite ore in Luanxian County of the present invention is staged ore grinding and gravity-magnetic process flow, and a certain maghemite ore in Luanxian County with a grade of 30% is fed into the sorting process of the present invention , to carry out subsequent grinding and sorting treatment, which specifically includes the following steps:

Step 1. A maghemite ore with a grade of 30% in Luanxian County is coarsely crushed and put into closed-circuit semi-autogenous grinding-screening operation, and the under-screen product (0-3mm) is fed into the magnetic weakening machine operation (field strength is 0.15T ), strong magnetic machine operation (the field strength is 1.0T) to carry out coarse particle sorting, the grade is 7.12%, the strong magnetic tailings of productive rate 32.43% is fed into the dewatering sieve for screening, and the sieve hole of the dewatering sieve is 0.3mm, and the sieve The upper product (0.3-3mm) is a coarse tailings product with a grade of 10.15% and a yield of 8.04%. The under-screen product (0-0.3mm) is a fine tailings with a grade of 6.12% and a yield of 24.39%. . The weak magnetic concentrate and strong magnetic concentrate are mixed into the primary grinding and grading system, and the overflow particle size reaches over 60% of -200 mesh, and then fed into the second magnetic separation operation (the field strength is 0.6T) for separation, and the discarded grade is 8.33%, the yield is 18.80% of the second magnetic separation tailings.

Step 2. The second magnetic separation concentrate with a grade of 53.57% and a yield of 48.77% is fed into the coarse and fine classification operation, and the coarse-grained sand settling product with a content of -200 mesh and 40% is selected by coarse and fine snails with a grade of 66.61 %, with a yield of 5.73%, the gravity separation concentrate, coarse snail tailings and fine snail tailings are mixed into the secondary closed-circuit grinding and grading system for operation, so that the overflow particle size of the secondary grading can reach -325 mesh 93%, and the grade is 51.18%, and the yield was 39.72%.

Step 3, the grade is 51.18%, the yield rate is 39.72% secondary classification overflow and -200 mesh content more than 85% fine-grained overflow product mixed ore is fed into three magnetic separation operations (field strength is 0.6T), Four magnetic separation operations (excitation current is 1.0A, rising water flow size is 1.1×10 ³ L/h), the magnetic separation concentrate with a grade of 65.58% and a yield of 31.98% is selected, and the three magnetic concentrates with a grade of 11.53% are discarded Separation tailings and four magnetic separation tailings with a grade of 13.81%.

Step 4. Gravity separation concentrate and magnetic separation concentrate are combined into final concentrate, with a grade of 65.74%; the grade of coarse tailings screened out by dehydration screen is 10.15%; fine tailings, second magnetic separation tailings, third The magnetic separation tailings and the four magnetic separation tailings are mixed into the final tailings with a grade of 8.10%.

Compared with stage grinding, coarse and fine separation, gravity separation-strong magnetic-anion reverse flotation process and continuous grinding (stage grinding) and magnetic-flotation process, the concentrate grade is basically the same, and the tailings are reduced by 1- 1.5%, 10-20% reduction in concentrate cost.

The above-mentioned embodiments are only used to illustrate and describe the present invention, and are not intended to limit the present invention to the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above-mentioned embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the present invention. Inside.

Claims (9)

1. A Anshan type maghemite sectional grinding and gravity-magnetic process flow is characterized by comprising the following steps:

(1) Coarsely crushing Anshan type maghemite with the grade of 25-30%, performing semi-autogenous grinding-screening system operation to obtain a product with the granularity of 0-3mm, sequentially sorting by a weak magnetic machine and a strong magnetic machine, mixing obtained concentrates, feeding the mixed concentrates into a primary grinding grading system, and screening obtained tailings and then respectively throwing the screened tailings;

(2) Performing secondary magnetic separation operation by a primary ore grinding and grading system until the overflow granularity reaches more than-200 meshes and the content is more than 60%, performing coarse and fine grading on the obtained secondary magnetic concentrate, and removing the obtained secondary magnetic tailings; the secondary magnetic separation concentrate is subjected to coarse and fine classification to obtain a coarse-grained settled sand product and a fine-grained overflow product, the coarse-grained settled sand product is subjected to coarse spiral separation and fine spiral separation in sequence to obtain gravity concentrate with the grade of more than 65%, coarse spiral tailings and fine spiral tailings, and the coarse spiral tailings and the fine spiral tailings are mixed and fed into a secondary grinding classification system;

(3) After passing through a secondary grinding and grading system until the overflow particle size reaches more than 90 percent of minus 325 meshes, mixing the overflow product with fine particles, and performing three-magnetic separation operation and four-magnetic separation operation to obtain magnetic concentrate with the grade of more than 65 percent, three-magnetic separation tailings and four-magnetic separation tailings; and the three-magnetic separation tailings and the four-magnetic separation tailings are removed, and the magnetic separation concentrate is mixed with the gravity concentrate to obtain concentrate with the grade of more than 65%.

2. The sectional grinding and gravity-magnetic process flow of the Anshan-type maghemite according to claim 1, wherein the Anshan-type maghemite of 25-30% grade can be other maghemite of 25-30% grade.

3. The sectional grinding and gravity-magnetic process flow of the Anshan-type maghemite according to claim 1, wherein the Anshan-type maghemite is coarsely crushed to a particle size of less than 300mm; the ore is separated by a weak magnetic machine and a strong magnetic machine in sequence, the obtained concentrate is mixed and then fed into a primary ore grinding classification system, and the obtained tailings are respectively removed after being screened, and the method specifically comprises the following steps: separating the mixture by a weak magnetic separator to obtain weak magnetic concentrate and weak magnetic tailings, separating the weak magnetic tailings by a strong magnetic separator to obtain strong magnetic concentrate and strong magnetic tailings, and mixing the weak magnetic concentrate and the strong magnetic concentrate and feeding the mixture into a primary grinding classification system; and screening the strong magnetic tailings to obtain coarse-grained tailings with the granularity of 0.3-3mm and fine-grained tailings with the granularity of 0-0.3 mm.

4. The sectional grinding and gravity-magnetic process flow of the Anshan type maghemite according to claim 1, wherein the coarse grit product is subjected to coarse spiral separation and fine spiral separation in sequence to obtain gravity concentrate with a grade of more than 65%, coarse spiral tailings and fine spiral tailings, and specifically comprises: and the coarse-grained settled sand product is subjected to coarse-spiral separation to obtain coarse-spiral concentrate and coarse-spiral tailings, and the coarse-spiral concentrate is subjected to fine-spiral separation to obtain gravity concentrate and fine-spiral tailings with the grade of more than 65%.

5. The Anshan-type maghemite sectional grinding and gravity-magnetic process flow as claimed in claim 1, wherein the magnetic concentrate with grade of more than 65% and the three and four magnetic tailings are obtained through three magnetic separation operations and four magnetic separation operations, and specifically comprises: and obtaining three-magnetic separation concentrate and three-magnetic separation tailings through three-magnetic separation operation, and feeding the three-magnetic separation concentrate into four-magnetic separation operation to obtain magnetic separation concentrate and four-magnetic separation tailings with the grade of more than 65%.

6. The sectional grinding and gravity-magnetic process flow of the Anshan type maghemite according to claim 1, wherein the coarse grit product has a-200 mesh content of 30-50%, and the fine overflow product has a-200 mesh content of more than 85%.

7. The sectional grinding and gravity-magnetic process flow of the Anshan type maghemite according to claim 3, characterized in that the fine tailings, the second magnetic separation tailings, the third magnetic separation tailings and the fourth magnetic separation tailings are mixed into tailings with 8-10% grade.

8. The sectional grinding and gravity-magnetic process flow of the Anshan type maghemite according to claim 1, wherein the magnetic separator adopted in the four magnetic separation operations is an elutriation machine; the excitation current of the elutriation machine is more than 1.0A; the field intensity of the weak magnetic machine is 0.15-0.2T; the field intensity of the strong magnetic machine is more than 1T; the field intensity of the second magnetic separation is 0.4-0.6T; the field intensity of the three-stage magnetic separation is 0.2-0.4T.

9. The Anshan-type maghemite sectional grinding and gravity-magnetic process flow as claimed in claim 1, wherein the grinding equipment of the semi-autogenous grinding-screening system comprises a semi-autogenous grinding machine, and the screening equipment comprises a linear screen; the tailing screening equipment in the step (1) comprises a dewatering screen; the ore grinding equipment of the primary ore grinding grading system comprises a ball mill; the ore grinding equipment of the secondary ore grinding grading system comprises a tower mill.

Images