CN111841870A

CN111841870A - Energy-saving and environment-friendly ultra-pure fine iron powder continuous production process

Info

Publication number: CN111841870A
Application number: CN201910349352.0A
Authority: CN
Inventors: 李明宇
Original assignee: Fushun Hanking Aoniu Mining Industry Co ltd
Current assignee: Fushun Hanking Aoniu Mining Industry Co ltd
Priority date: 2019-04-28
Filing date: 2019-04-28
Publication date: 2020-10-30

Abstract

The invention relates to an energy-saving and environment-friendly ultra-pure fine iron powder continuous production process. The invention has high resource utilization rate, low production cost and no wastewater discharge. The invention comprises the following steps: grinding and selecting: crushing and tailing discarding of raw ore, fine crushing and tailing discarding, grinding and grading of tailing discarding concentrate in a ball mill, magnetic separation of a grading product in a magnetic separator to obtain concentrate with the grade of 68-69%, 67-70% of concentrate-200 meshes and SiO₂The content is 4.5-5.5%; b, fine grinding and selecting: screening the conventional magnetic concentrate by-200 meshes, performing dehydration and magnetic separation on the product under the screen, then feeding the product into a tower mill for fine grinding, feeding the overflow of the tower mill into a cyclone for classification, feeding the classification overflow with the fineness of-500 meshes accounting for more than 75% of the product into a magnetic separator for classification, feeding the underflow back to the tower mill, and feeding the iron concentrate obtained by the classification into an electromagnetic concentration machine for concentration; c, reverse flotation: the bottom flow of the electromagnetic concentrator with the grade of 71-71.4% flowing into the stirring barrel is subjected to size mixing, the size mixing concentration is 30%, and the pH value is neutral; the ore pulp enters a flotation machine for reverse flotation, and the ore pulp is filtered to obtain acid insoluble substances with the grade of 72.10-72.15%, the content of SiO2 of less than 0.07%, and the grade of The content of the super-pure fine iron powder is less than 0.15 percent.

Description

Energy-saving and environment-friendly ultra-pure fine iron powder continuous production process

Technical Field

The invention relates to a production process of fine iron powder, in particular to an energy-saving and environment-friendly continuous production process of ultra-pure fine iron powder.

Background

The ultra-pure fine iron powder is prepared from (by weight) iron grade of 71.50-72.0% and SiO₂Iron ore concentrate powder with content lower than 0.3% and acid insoluble substance lower than 0.15%. The ultra-pure fine iron powder is widely applied to powder metallurgy, production of metallized pellets and magnetic materials, and can also be used in the fields of chemical industry, environmental protection, food preservation, sewage treatment, medicine and the like. The research on the classification of super iron ore concentrate is carried out at home and abroad in the 20 th century, but the requirement of ultra-pure iron ore concentrate on the content of impurities is very high, particularly SiO₂The content and the content of acid insoluble substances cause the high-grade fine iron powder produced by a plurality of concentrating mills to have super total iron indexOver 71.50% but SiO₂And the content of acid insoluble substances is higher than the index, so that the use requirement cannot be met. The existing method for industrially producing super fine iron powder mainly comprises the steps of carrying out two-stage continuous ball mill grinding on rough concentrate by using a traditional ball mill, carrying out size mixing and cation reverse flotation after the degree of dissociation is achieved, and the process is not easy to adjust due to poor index stability and large influence of ore fineness. The process has several problems: 1. when the traditional ball mill is used for superfine grinding, the energy consumption is high, the efficiency is low, and the consumption of grinding media is high; 2. the ground ore product directly enters into reverse flotation, the flotation agent can collect the dissociated and partially dissociated particles, but the wrapped type intergrowth cannot be collected, so that the wrapped type intergrowth only can enter into reverse flotation concentrate, and the index stability of the ultrapure iron concentrate is poor; 3. because the ore grinding products are all fed into the flotation process, the agent consumption is large, the flotation wastewater is more, the production cost is greatly improved, and the discharge of the wastewater has the problem of environmental protection.

Disclosure of Invention

Aiming at the problems, the invention provides an energy-saving and environment-friendly ultra-pure fine iron powder continuous production process, which can improve the utilization rate of mineral resources, reduce the production cost and avoid wastewater discharge in the production process.

In order to achieve the purpose, the invention adopts the following scheme: an energy-saving and environment-friendly ultra-pure fine iron powder continuous production process comprises the following steps:

grinding and selecting: crushing and tailing discarding of raw ore, fine crushing and tailing discarding, grinding and grading of tailing discarding concentrate in a ball mill, magnetic separation of a grading product in a magnetic separator to obtain concentrate with the grade of 68-69%, 67-70% of concentrate-200 meshes and SiO₂The content is 4.5-5.5%;

b, fine grinding and selecting: screening the conventional magnetic concentrate by-200 meshes, performing dehydration and magnetic separation on the product under the screen, then feeding the product into a tower mill for fine grinding, feeding the overflow of the tower mill into a cyclone for classification, feeding the classification overflow with the fineness of-500 meshes accounting for more than 75% of the product into a magnetic separator for classification, feeding the underflow back to the tower mill, and feeding the iron concentrate obtained by the classification into an electromagnetic concentration machine for concentration;

c, reverse flotation: the bottom flow of the electromagnetic concentrator with the grade of 71-71.4% flowing into the stirring barrel is subjected to size mixing, the size mixing concentration is 30%, and the pH value is neutral; and (3) performing reverse flotation on the ore pulp in a flotation machine, and filtering to obtain the ultrapure fine iron powder with the grade of 72.10-72.15%, the content of SiO2 of less than 0.07% and the content of acid insoluble substances of less than 0.15%.

Further, the reverse flotation in the step C comprises primary roughing and secondary scavenging, the reverse flotation agent is dodecylamine, and the adding amount is 150-200 g/t.

And further, the wastewater generated in the reverse flotation in the step C flows through the flotation circulating water tank and then enters the flotation machine again to participate in the reverse flotation.

Further, the present invention further comprises step D: and D, filtering the underflow of the magnetic separator in the step A, the overflow of the electromagnetic separator in the step B and the reverse flotation foam in the step C to obtain the common refined iron powder with the grade of 66-66.5%.

Further, the present invention further comprises step E: and D, returning the filtrate obtained in the step D to the ball mill in the step A, and performing primary ore grinding classification.

Advantageous effects of the invention

The invention improves the fine grinding process, the fine grinding in the traditional process uses a ball mill, usually two to three sections of ball mills are needed to grind ores in a continuous grading way, the fineness can reach about 70 percent of the selected fineness of 400 meshes, the invention only uses one tower mill to carry out fine grinding, and can reach the fineness requirement, compared with the previous method of carrying out fine grinding by using a ball mill, the invention has the advantages of less used equipment and simple configuration, reduces the process, reduces the equipment investment and reduces the investment cost; because the tower mill is selected as the fine grinding equipment, the energy consumption of ore grinding is greatly reduced; the byproducts of the three steps are processed and sold as common iron concentrate powder, so that the utilization rate of mineral resources is improved; the reverse flotation wastewater and the filtrate are recycled, so that the environmental pollution caused by direct discharge of the wastewater is avoided, and meanwhile, the water resource is saved and the waste is avoided; the reverse flotation wastewater flows through the flotation circulating water tank and then enters the flotation machine again, so that the consumption of the medicament is reduced; meanwhile, the problem of emission is solved, and the environmental protection effect is good. The invention is suitable for a concentrating mill to add a fine processing line on the original production line and also suitable for building an independent iron fine processing line, and has wide application range.

Detailed Description

The method comprises the steps of grinding raw ore by one section or two sections, crushing and tailing discarding, then carrying out wet screening by a high-pressure roller mill to carry out closed-circuit fine crushing, carrying out coarse particle tailing discarding on the fine crushed material, carrying out first-section grinding classification on tailing discarding concentrate, and then carrying out magnetic separation on the material, wherein the fineness of the magnetically-separated material-200 is 65-70%, the grade is 68-68.5%, and SiO is₂The content of the magnetic separation material is 4.5-5.5%, the magnetic separation material is subjected to cyclone pre-classification, the fineness of 200 classification underflow is used as a byproduct I, the fineness of classification overflow material is-200 meshes 90%, the overflow material is subjected to dehydration magnetic separation and then enters a tower mill for fine grinding, the overflow of the tower mill enters a classification cyclone, the classification underflow returns to the tower mill for closed circuit grinding, the fineness of classification overflow is-500 meshes 60-75%, the classification overflow product enters a magnetic separator for separation, the separation product enters an electromagnetic separator for separation, the overflow of the electromagnetic separator is used as a byproduct II, the underflow grade of the separator is 71-71.5%, the classification underflow enters a pulp mixing barrel for pulp mixing, the pulp mixing concentration is 30%, the pulp after pulp mixing enters a flotation machine, the chemical is dodecylamine, and the adding amount is 40-70 g/t. Performing magnetic roughing twice scavenging, using a flotation foam product as a byproduct III, and filtering concentrate obtained by reverse flotation to obtain iron concentrate with the grade of 72.10-72.15% and SiO ₂0.06-0.07% of the total amount of the acid-insoluble substance and 0.09-0.15% of the total amount of the acid-insoluble substance. And filtering the byproducts I, II and III to obtain 66-66.5% grade common iron fine powder, and returning the filtrate to the first-stage ore grinding for reuse. The wastewater generated in the process of grinding classification and magnetic separation has no flotation reagent pollution and is directly discharged into a thickening tank for treatment, the concentrated bottom flow of tailings is discharged into a tailing pond, the overflow water enters a production water pond for recycling, and the wastewater generated in the process of flotation enters a flotation circulating water pond for recycling in the flotation link without discharge.

Examples

The specific data of the invention are shown in the following tables 1-5, taking metal minerals mainly comprising magnetite, and taking limonite, a small amount of pyrrhotite, a trace amount of chalcopyrite and the like as raw ores.

Two-stage one-closed-circuit crushing is carried out on the raw ore, the crushed product is less than 3mm, the crushed material is ground, the fineness is-200 meshes and accounts for 65%, and a magnetic separator is used for sorting. The sorting results are shown in Table 1.

TABLE 1 magnetic separation results

The concentrate was classified by 200 mesh and the classification results are shown in table 2.

Table 2 concentrate grading results

And (3) grinding the classified products to the fineness of-500 meshes and 75%, and sorting the ground products by a fine sorting machine, wherein sorting results are shown in a table 3.

Table 3 electromagnetic cleaner concentrate classification results

And performing reverse flotation on the bottom flow of the electromagnetic fine separator, and adopting a process of once roughing and twice scavenging. The flotation froth products were combined and mixed with the +200 mesh concentrate of table 2, the cleaner overflow of table 3 as a by-product concentrate. The pH value of the flotation ore pulp is neutral, the dosage of the dodecylamine is 70g/t, the reverse flotation concentrate is 72.15 percent, and the SiO content is₂The content is 0.06 percent, and the content of acid insoluble substances is less than 0.15 percent. The flotation results are shown in Table 4. The mass balance of the selections is shown in Table 5.

TABLE 4 flotation results

TABLE 5 number of mass balance table

Claims

1. An energy-saving and environment-friendly ultra-pure fine iron powder continuous production process is characterized by comprising the following steps:

2. The process of claim 1, wherein the reverse flotation comprises one roughing and two scavenging, and the reverse flotation is dodecylamine added in an amount of 150-200 g/t.

3. The process of claim 2, wherein the wastewater from the reverse flotation step C is passed through a flotation circulating water tank and then re-introduced into the flotation machine to participate in the reverse flotation.

4. The energy-saving and environment-friendly continuous production process of the ultra-pure fine iron powder as claimed in claim 1, 2 or 3, characterized in that the underflow of the magnetic separator in the step A, the overflow of the electromagnetic separator in the step B and the reverse flotation foam in the step C are filtered to obtain the common fine iron powder with the grade of 66-66.5%.

5. The energy-saving and environment-friendly ultra-pure fine iron powder continuous production process as claimed in claim 1, characterized in that the invention comprises the steps of D: and D, filtering the underflow of the magnetic separator in the step A, the overflow of the electromagnetic separator in the step B and the reverse flotation foam in the step C to obtain the common refined iron powder with the grade of 66-66.5%.

6. The process of claim 1 or 5, wherein the process comprises the following steps: and D, returning the filtrate obtained in the step D to the ball mill in the step A, and performing primary ore grinding classification.