CN113667820A - Comprehensive and efficient utilization method of Mongolian iron ore - Google Patents

Abstract

The invention discloses a method for comprehensively and efficiently utilizing Mongolian iron ores, which is implemented by a technical scheme of comprehensively utilizing Mongolian iron ores, and provides an optimal scheme for economically and reasonably utilizing Mongolian ore resources by technical means of classified use of Mongolian iron ores, improvement of high-sulfur Mongolian ore selection ratio, increase of Mongolian iron ore matching proportion and the like. By implementing the technical scheme of the invention, the beneficiation cost of the Mongolian iron ore can be reduced, the addition proportion of the Mongolian iron ore in sintering is increased, the raw material purchasing cost of the sinter is reduced, and the economic benefit is very obvious.

Description

Comprehensive and efficient utilization method of Mongolian iron ore

Technical Field

The invention relates to the field of metallurgical ironmaking raw material production, in particular to a comprehensive and efficient utilization method of Mongolian iron ore.

Background

The main raw material for blast furnace iron making is iron ore, and China needs to import a large amount of Australian iron ore and Brazil iron ore every year. China has high dependency on Australian and Brazilian iron ores, and the pricing right is limited. With the continuous surge of the price of the iron ore, the cost of the blast furnace raw materials is also increased continuously, and the profit margin of the iron and steel enterprises is compressed continuously. The search of high cost performance iron ore resources to replace imported marine ore with higher price is a favorable means for reducing the cost of iron-making raw materials of iron and steel enterprises. The Mongolian iron ore has abundant resources but most of the ores have higher sulfur content, and domestic enterprises carry out a great deal of research on developing and using Mongolian iron ores, and the research results are listed as follows:

in the united colleges of certain iron and steel enterprises in China, systematic process mineralogy research is carried out on iron ores mined in certain mines in Mongolia. The result shows that the iron grade of the ore is 45.53 percent, and the content of impurity sulfur is higher; the iron-containing minerals of the ore mainly comprise magnetite and a small amount of hematite and limonite; the other metal minerals are mainly pyrite, and a small amount of chalcopyrite, trace copper blue, blue chalcocite, pyrrhotite, rutile and the like are also contained. Aiming at the properties of ores, the process flow of coarse grinding, magnetic separation and tailing discarding and coarse concentrate regrinding to remove impurities such as sulfur, silicon and the like is adopted for sorting, and all quality indexes of the produced iron concentrate can meet the use requirements of pellets. The research of the Mongolia lump ore directly entering the furnace by professor Wushengli of Beijing university of science and technology shows that the Mongolia lump ore has the characteristics of compact structure, difficult reduction and the like, and is not suitable to be used as a raw material to directly enter a blast furnace.

The periteel achieves better research results in the technical research of processing and treating Mongolia high-sulfur blocks or powder ore high-sulfur Mongolia powder ore to produce iron ore concentrate. The Mongolian iron ore mainly has a blocky structure and a dip-dyed structure, and secondly has a net-vein-shaped structure and a stripe-shaped structure; the structure of the ore mainly comprises a semi-self-shape-other-shape granular structure, an alternate residual structure, a false structure, a crushing structure and a self-shape crystal structure; magnetite is mostly distributed in gangue mineral in the form of semi-self-shape-other shape crystal grain and aggregate thereof, the gangue mineral in the aggregate is seen to be distributed along the clearance of magnetite particles in the form of grain or fine grain, the embedded grain size of the magnetite is mainly medium grain, and the distribution rates of the coarse grain, the medium grain and the fine grain are respectively 32.43 percent, 39.63 percent and 27.03 percent; the statistical result of the monomer dissociation degree of the magnetite under different grinding fineness shows that most of the magnetite is easy to dissociate in the grinding process and the magnetite is easy to recover. The Mongolian iron ore can be treated by adopting a magnetic separation and flotation desulphurization process to produce iron ore concentrate for pellet use.

Disclosure of Invention

Because the mineral separation process of the high-sulfur Mongolian fine ore is complex and has high separation rate, and the produced iron ore concentrate has high sulfur content, the economy of using Mongolian iron ore is not obvious. The invention relates to a method for comprehensively and efficiently utilizing Mongolian iron ores, which is implemented by a technical scheme of comprehensively utilizing Mongolian iron ores, and provides an optimal scheme for economically and reasonably utilizing Mongolian ore resources by technical means of classified use of Mongolian iron ores, improvement of high-sulfur Mongolian ore selection ratio, increase of matching proportion of Mongolian iron ores and the like.

In order to solve the technical problems, the invention adopts the following technical scheme:

the invention relates to a method for comprehensively and efficiently utilizing Mongolian iron ores, which comprises the following steps of:

according to the detection and analysis of the physicochemical properties of the Mongolian iron ores, the Mongolian iron ores are classified and utilized, and the classification method comprises the following steps:

variety of ore	TFe	SiO2	S
				High-grade high-sulfur powder (lump) ore	57-62	4.5-5.5	2.5-4.0
Low grade high sulfur powder (lump) ore	50-57	4.5-5.5	2.5-4.0
				Pyrite concentrate	65-67	2.5-3.5	0.9-1.5
Low sulphur iron concentrate	65-67	2.5-4.5	<0.5
				Low sulfur Mongolian fine ore	57-62	4.5-5.5	<0.5

The process for producing the sinter by setting the low-sulfur Mongolia powder ore to replace Australian ore to carry out batching comprises the following steps: preparing sintered ore by taking 45% of sulfur bulk concentrate, 45% of Australian fine ore and 10% of low-sulfur Mongolia fine ore as iron materials for sintering; wherein the sulfur bulk concentrate is prepared by proportioning domestic concentrate and the iron ore of Mongolia according to a proportion and carrying out magnetic separation;

the technical quality standard and the technical scheme of producing the sulfur bulk iron concentrate from the high-sulfur Mongolian powder (lump) ore through magnetic separation of a concentrating mill and a flotation desulfurization process are set, if the sulfur bulk iron concentrate produced by the fine crushing and grinding magnetic separation process does not meet the technical quality standard, the flotation desulfurization process is added to the Mongolian concentrate, and the process flow and the process parameters are adjusted according to the index of the bulk iron concentrate.

Further, the main sintering control process parameters for producing the sinter are as follows: the alkalinity of the sintered ore is 1.95-2.05, and the mass percentage of MgO in the sintered ore is 1.90-2.10%; the mass percentage of the water in the mixture is 7.0-9.0%.

Further, the specific steps for producing the sinter are as follows: granulating the mixture, wherein the time of the granulating process is controlled to be 4-6 min;

distributing the granulated mixture;

igniting the mixture arranged on the sintering device, wherein the ignition time is controlled to be 1-3 min, and the ignition negative pressure is 4000-6000 Pa;

the sintering process is accompanied with air draft treatment, the negative pressure of the air draft is 9000-12000 Pa, and the sintering end point temperature is controlled at 200-300 ℃.

Compared with the prior art, the invention has the beneficial technical effects that:

the Mongolian iron ores are classified according to chemical components and physical properties, the low-sulfur Mongolian powder ore is directly used in sintering ingredients, the high-sulfur Mongolian powder ore is mixed with domestic iron ores to produce sulfur bulk concentrate for the sintering ingredients through crushing, grinding, magnetic separation and flotation processes, and the selection ratio of the high-sulfur Mongolian powder ore to produce the concentrate is reduced. By implementing the technical scheme of the invention, the beneficiation cost of the Mongolian iron ore can be reduced, the addition proportion of the Mongolian iron ore in sintering is increased, the raw material purchasing cost of the sinter is reduced, and the economic benefit is very obvious.

Drawings

The invention is further illustrated in the following description with reference to the drawings.

FIG. 1 is a flow chart of the comprehensive efficient utilization method of Mongolian iron ore.

Detailed Description

As shown in fig. 1, a method for comprehensively and efficiently utilizing Mongolian iron ore comprises the following steps:

firstly, detecting and analyzing chemical components of the high-sulfur Mongolian powder ore:

variety of ore	TFe	SiO2	S
				Low grade high sulfur powder (lump) ore	53	4.5	4

The domestic concentrate and the low-grade high-sulfur powder (lump) ore are mixed by the following ratio of 2: 1 ore proportioning ratio, and controlling the sulfur and iron ore concentrate according to the S content of less than 1.25%. And if the sulfur content of the mixed iron ore concentrate exceeds the standard, starting a Mongolia concentrate flotation desulfurization process to ensure that the quality of the sulfur-containing mixed iron ore concentrate is qualified.

And (4) carrying out sintering burdening calculation according to 45% of sulfur bulk concentrate, 45% of Australian fine ore and 10% of low-sulfur Mongolia fine ore, and calculating the sintering flux and fuel ratio. The components of the raw fuel used for sintering and the ore blending scheme are shown in tables 1 and 2.

TABLE 1 chemical composition of raw fuel for sintering (wt%)

TABLE 2 raw material ratio (wt%)

TABLE 3 chemical composition and Process index of sintered ore of examples

The raw materials and the mixture ratio shown in the table 1 and the table 2 are mixed. Adding water into the raw materials in a primary mixer, and uniformly mixing, wherein the water content is controlled to be 7.5%; then granulating in a secondary mixer for 5 min; the mixture after granulation is uniformly distributed to a sintering machine through a distributor, and the thickness of a material layer is 700 mm. And adjusting the machine speed of the sintering machine and the opening degree of an air door of an exhaust fan, and controlling the sintering negative pressure and the sintering end point temperature to finish the sintering production process.

The chemical composition and process index of the sintered ore are shown in table 3. As can be seen from tables 2 and 3:

solid burnup aspect: compared with the reference example, the sulfur bulk concentrate is used to replace domestic concentrate, and the solid fuel consumption is slightly reduced. In the aspect of drum strength: the drum strength of example 1 was increased as compared with the reference example. Sintered ore TFe aspect: TFe was slightly higher than that of the reference example.

The embodiment comprises the following steps of (1) economic benefit measurement: the iron ore concentrate is produced by mineral separation of the high-sulfur Mongolian powder ore by applying the technology of the invention, the S content is controlled to be 1.2-1.8 from 0.8-1.0 of the original scheme, the selection ratio is reduced to 1.375 from 1.428, and the production cost of the iron ore concentrate is reduced by 41 yuan/ton. The low-sulfur Mongolia fine ore is used for replacing Australian fine ore, so that the purchasing cost of the sintered iron material can be reduced by 120 yuan/ton. The 40 ten thousand tons of low-sulfur Mongolian powder ore are used in the year, and the economic benefit can be created by 40X 120+ 100X 41-4580X yuan per year after the measurement of 100 ten thousand tons of Mongolian concentrate.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims (3)

1. A method for comprehensively and efficiently utilizing Mongolian iron ore is characterized by comprising the following steps: the method comprises the following steps:

according to the detection and analysis of the physicochemical properties of the Mongolian iron ores, the Mongolian iron ores are classified and utilized, and the classification method comprises the following steps:

variety of ore TFe SiO2 S High-grade high-sulfur powder (lump) ore 57-62 4.5-5.5 2.5-4.0 Low grade high sulfur powder (lump) ore 50-57 4.5-5.5 2.5-4.0 Pyrite concentrate 65-67 2.5-3.5 0.9-1.5 Low sulphur iron concentrate 65-67 2.5-4.5 <0.5 Low sulfur Mongolian fine ore 57-62 4.5-5.5 <0.5

The process for producing the sinter by setting the low-sulfur Mongolia powder ore to replace Australian ore to carry out batching comprises the following steps: preparing sintered ore by taking 45% of sulfur bulk concentrate, 45% of Australian fine ore and 10% of low-sulfur Mongolia fine ore as iron materials for sintering; wherein the sulfur bulk concentrate is prepared by proportioning domestic concentrate and the iron ore of Mongolia according to a proportion and carrying out magnetic separation;

the technical quality standard and the technical scheme of producing the sulfur bulk iron concentrate from the high-sulfur Mongolian powder (lump) ore through magnetic separation of a concentrating mill and a flotation desulfurization process are set, if the sulfur bulk iron concentrate produced by the fine crushing and grinding magnetic separation process does not meet the technical quality standard, the flotation desulfurization process is added to the Mongolian concentrate, and the process flow and the process parameters are adjusted according to the index of the bulk iron concentrate.

2. The method for comprehensively and efficiently utilizing the Mongolian iron ore according to claim 1, which is characterized in that: the main technological parameters of controlled sintering for producing sintered ore are as follows: the alkalinity of the sintered ore is 1.95-2.05, and the mass percentage of MgO in the sintered ore is 1.90-2.10%; the mass percentage of the water in the mixture is 7.0-9.0%.

3. The method for comprehensively and efficiently utilizing the Mongolian iron ore according to claim 1, which is characterized in that: the specific steps for producing the sinter are as follows: granulating the mixture, wherein the time of the granulating process is controlled to be 4-6 min;

distributing the granulated mixture;

igniting the mixture arranged on the sintering device, wherein the ignition time is controlled to be 1-3 min, and the ignition negative pressure is 4000-6000 Pa;

the sintering process is accompanied with air draft treatment, the negative pressure of the air draft is 9000-12000 Pa, and the sintering end point temperature is controlled at 200-300 ℃.

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