CN114849856B - A production method for fine grinding of blast furnace return ore - Google Patents

Abstract

The production method of fine grinding of blast furnace return ore provided by the present invention relates to the field of mineral processing technology. The production method of fine grinding of blast furnace return ore includes: subjecting ore materials to feeding and screening treatment to separate the ore materials into oversize materials and undersize materials; sending the oversize materials into the blast furnace for ironmaking; subjecting the undersize materials to a beneficiation ball milling process and a concentration and filtration process to prepare the undersize materials into iron concentrate, wherein the iron concentrate is included in the ore materials. The production method of fine grinding of blast furnace return ore provided by the present invention utilizes blast furnace return ore to process into a new variety of iron concentrate, which is beneficial to the adjustment of the pellet raw material structure and the control of quality. At the same time, it can also solve or partially solve the problem of high cost caused by foreign transportation.

Description

A production method for fine grinding of blast furnace return ore

Technical Field

The invention relates to the technical field of ore dressing, in particular to a production method for fine grinding of blast furnace return ore.

Background technique

Large-proportion pelletizing is the development direction of domestic blast furnace ironmaking, but currently there are few types of iron ore concentrate that can be used for pellet production, with a single structure, low grade and many impurities in domestic iron ore concentrate, and high price due to the long transportation distance of foreign iron ore concentrate. In other words, in large-proportion pelletizing blast furnace ironmaking, there are problems of low grade and high cost of iron ore concentrate that need to be solved urgently.

Summary of the invention

The purpose of the present invention includes, for example, providing a production method for fine grinding of blast furnace return ore, which utilizes blast furnace return ore to process into a new variety of iron ore concentrate, which is beneficial to the adjustment of pellet raw material structure and quality control. At the same time, it can also solve or partially solve the problem of high cost caused by foreign transportation.

The embodiments of the present invention can be implemented as follows:

The embodiment of the present invention provides a production method for fine grinding of blast furnace return ore, comprising:

The ore material is subjected to a feeding and screening process to separate the ore material into an oversize material and an undersize material;

sending the above-screen materials into a blast furnace for ironmaking;

The undersize material is subjected to a beneficiation ball milling process and a concentration and filtration process to prepare the undersize material into an iron ore concentrate, wherein the iron ore concentrate is included in the ore material.

Further, in an optional embodiment, the ore dressing ball milling process includes:

Performing a first grinding process on the undersize material by a first ball mill;

Classifying the pulp processed by the first grinding process by a first cyclone;

The overflow of the first cyclone is subjected to a second classification process by means of a second cyclone;

The overflow of the second cyclone is subjected to the concentration and filtration process to prepare the iron ore concentrate.

Furthermore, in an optional embodiment, the ore dressing ball milling process further comprises:

The bottom flow of the first cyclone is returned to the first ball mill for re-grinding.

Further, in an optional embodiment, the ore dressing ball milling process further includes:

performing a second grinding process on the underflow of the second cyclone by a second ball mill;

The ore pulp treated by the second grinding process is classified by the second cyclone.

Further, in an optional embodiment, the ore dressing ball milling process includes:

Performing a first grinding process on the undersize material by a first ball mill to form a first ore pulp;

performing classification treatment on the first slurry by a first cyclone;

Returning the underflow of the first cyclone to the first ball mill for re-grinding;

The overflow of the first cyclone is subjected to a concentration and filtration process to prepare the iron ore concentrate.

Further, in an optional embodiment, the concentration and filtration process includes:

The ore pulp after the ore dressing ball milling process is concentrated and filtered to form the iron concentrate and circulating water;

The iron ore concentrate is added to the ore material, and the ore material is subjected to the step of feeding and screening to separate the ore material into an oversize material and an undersize material;

The circulating water is introduced into the first cyclone and/or the second cyclone.

Further, in an optional embodiment, in the step of subjecting the ore material to feeding and screening to separate the ore material into oversize material and undersize material, the size range of the screening process is between 6.0 mm and 6.5 mm.

Further, in an optional embodiment, in the ore dressing ball milling process, the grinding power index is set to 35 kW·h/t.

Furthermore, in an optional embodiment, in the mineral processing ball milling process, the ball mill adopts a long cylinder mill with a length greater than 7 meters.

Further, in an optional embodiment, in the mineral processing ball milling process, the cyclone cone is less than 20 degrees.

The production method of fine grinding of blast furnace return ore provided by the present invention has the following beneficial effects: the present invention utilizes blast furnace return ore to process into a new variety of iron ore concentrate, which is beneficial to the adjustment of pellet raw material structure and quality control. At the same time, it can also solve or partially solve the problem of high cost caused by foreign transportation.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative work.

FIG1 is a schematic flow chart of a production method for fine grinding of blast furnace return ore according to a specific embodiment of the present invention;

FIG2 is a schematic flow chart of the ore dressing ball milling process in step S300 in FIG1 ;

FIG3 is a schematic flow diagram of a production method for fine grinding of blast furnace return ore according to a specific embodiment of the present invention.

Icons: 1-feeding and screening device; 2-first ball mill; 3-first cyclone; 4-second cyclone; 5-second ball mill; 6-concentration and filtration device; 7-circulating water pipeline; 8-iron concentrate circuit.

Detailed ways

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

Large-proportion pellets are the development direction of domestic blast furnace ironmaking, but the types of iron concentrates that can be used for pellet production are few and the structure is single. The domestic iron concentrate has low grade and many impurities. The foreign iron concentrate has long transportation distance and high price. The present invention proposes a new blast furnace return ore fine grinding production method, adding a finely ground pellet powder as an ore resource; blast furnace return ore is the screening undersize before pellets, sintered ore, lump ore and other materials enter the blast furnace, mainly composed of small-particle sintered ore and small broken balls. Because sintering and pellets are formed through high-temperature liquid phase, they have high hardness, high wear resistance, high grinding work index, and high difficulty in fine grinding. The present invention can improve or solve the above problems. It uses blast furnace return ore to process into a new variety of iron concentrate, which is conducive to the adjustment of pellet raw material structure and quality control. At the same time, it can also solve or partially solve the problem of high cost caused by foreign transportation.

Please refer to FIG1 . This embodiment provides a production method for fine grinding of blast furnace return ore, which includes the following steps.

Step S100: subjecting the ore material to a feeding and screening process to separate the ore material into oversize material and undersize material.

Further, in step S100 of subjecting the ore material to screening to separate the ore material into the oversize material and the undersize material, the size range of the screening process is between 6.0 mm and 6.5 mm. Optional ID, the size of the screening process is set to 6.3 mm. Of course, it can also be set to any other value within the above range.

Step S200: sending the material on the screen into the blast furnace for ironmaking.

Step S300: performing a beneficiation ball milling process and a concentration and filtration process on the undersize material to prepare the undersize material into iron concentrate, wherein the iron concentrate is included in the ore material.

It should be pointed out that in step S300, the undersize material in step S100 can be supported into iron concentrate through the ore dressing ball milling process and the concentration and filtration process. The iron concentrate passes through step S100 again and enters the screening process again, and finally enters step S200 for blast furnace ironmaking. In other words, the present invention can prepare undersize material that is not suitable for blast furnace ironmaking into iron concentrate that can be used for blast furnace ironmaking. On the one hand, the blast furnace return ore is used to process into a new variety of iron concentrate, which is conducive to the adjustment of the pellet raw material structure and the control of quality, improves the utilization rate of minerals, and reduces costs; at the same time, it can also solve or partially solve the problem of high cost caused by foreign transportation.

Please refer to FIG. 2 , in an optional embodiment, the ore dressing ball milling step S310 may include the following steps.

Step S311: performing a first grinding process on the undersize material by using a first ball mill.

Step S312: Classifying the pulp obtained from the first grinding process by means of a first cyclone.

Step S313: The overflow of the first cyclone is subjected to a second classification process by the second cyclone.

Step S314: performing a concentration and filtration process on the overflow of the second cyclone to prepare iron ore concentrate.

It should be understood that in the present invention, by grinding the undersize material, classifying it twice, and then concentrating and filtering the overflow of the second cyclone, iron concentrate can be prepared, thereby improving the utilization of the undersize material.

Furthermore, the ore dressing ball milling process may also include step S315: returning the underflow of the first cyclone to the first ball mill for re-grinding treatment.

Furthermore, the beneficiation ball milling process may also include step S316: performing a second grinding process on the underflow of the second cyclone by a second ball mill; and step S317: performing a classification process on the slurry of the second grinding process by the second cyclone. The second grinding process can better utilize the undersize material, thereby improving its utilization rate.

It should be noted that in the beneficiation ball milling process, the grinding power index is set to 35kW·h/t. The ball mill adopts a long simple mill with a length greater than 7 meters. The cyclone cone is less than 20 degrees. Of course, it is not limited to this. In other embodiments of the present invention, other parameters can also be set, and the embodiments of the present invention do not make specific requirements and limitations on this.

In addition, it should be pointed out that in other embodiments of the present invention, the ore dressing ball milling process may also include a primary grinding process. In this case, the ore dressing ball milling process may also include:

S321: Performing the first grinding process on the undersize material through the first ball mill;.

S322: Classify the ore pulp from the first grinding process through the first cyclone.

S323: Return the bottom flow of the first cyclone to the first ball mill for re-grinding.

S324: The overflow of the first cyclone is subjected to a concentration and filtration process to prepare an iron ore concentrate.

In the above steps S321 to S324, the undersize material is subjected to a grinding process. For some ore materials, a grinding process is sufficient; while for more ore materials, they can be processed through the above steps S311 to S317. The embodiment of the present invention can select one of the above two ore dressing ball milling processes according to different ore materials.

Please refer to FIG. 3 , in an optional embodiment, the concentration and filtration process S330 includes the following steps.

Step S331: concentrate and filter the slurry after the beneficiation ball milling process to form iron concentrate and circulating water; Step S332: add the iron concentrate to the ore material, and perform feeding and screening on the ore material to separate the ore material into the above-screen material and the below-screen material; Step S333: introduce the circulating water into the first cyclone and/or the second cyclone.

Please refer to Figures 2 and 3. In the present invention, after a certain proportion of ore materials such as pellets, sintered ore, and lump ore are screened by the feeding screening device 1, the screened materials enter the blast furnace for ironmaking, and the screened materials enter the ore dressing ball milling process and the concentration and filtration process. The ore entering the ore dressing ball milling process first passes through the first ball mill 2 for grinding, and the ore pulp after grinding enters the first cyclone 3 for classification treatment. The bottom flow of the first cyclone 3 returns to the first ball mill 2 for re-grinding, and the overflow of the first cyclone 3 enters the second cyclone 4 for re-classification. The fine-grained ore pulp after the secondary classification enters the concentration and filtration device 6 for the concentration and filtration process, and the coarse-grained bottom flow ore pulp classified by the second cyclone 4 returns to the second ball mill 5 for re-grinding, and the second cyclone and the second ball mill 5 form a closed loop. The slurry enters the concentration and filtration process of the concentration and filtration device 6. The concentration is increased to 60% by the thickener, and then filtered by the vacuum filter to produce iron concentrate. The moisture content of the iron concentrate can meet the requirement of <10%. The iron concentrate returns to the feeding and screening device 1 through the iron concentrate circuit 8; the concentrated overflow and filtered out circulating water can be recycled through the circulating water pipeline 7, and reused through the double suction pump meshing and the first and second ball milling process. The whole process has zero external discharge, no pollution, environmental protection and energy saving, and the output iron concentrate is transported to the pelletizing plant as raw material for manufacturing pellets.

Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims (5)

1. The production method of the blast furnace return ore fine grinding is characterized by comprising the following steps of:

Feeding and screening the ore material to separate the ore material into an oversize material and an undersize material, wherein the ore material comprises pellets, sinter and lump ore, and the size range of the screening treatment is 6.0mm-6.5 mm;

feeding the oversize material into a blast furnace for iron making;

Carrying out a mineral separation ball milling process and a concentration filtering process on the undersize material so as to prepare Cheng Tie concentrate from the undersize material, wherein the moisture content of the iron concentrate is less than 10%, and the iron concentrate returns to a feeding screening device through an iron concentrate loop to be circularly subjected to feeding screening treatment; the mineral separation ball milling process comprises the following steps:

Carrying out primary grinding treatment on the undersize material through a first ball mill;

Classifying the ore pulp subjected to the first ore grinding treatment through a first cyclone;

carrying out grading treatment again on overflow of the first cyclone through a second cyclone;

Performing the concentration and filtration process on the overflow of the second cyclone to prepare the iron concentrate;

Returning the underflow of the first cyclone to the first ball mill for secondary grinding treatment;

carrying out secondary ore grinding treatment on the underflow of the second cyclone through a second ball mill;

classifying the ore pulp subjected to the second ore grinding treatment through the second cyclone;

the concentration and filtration process comprises the following steps:

concentrating and filtering ore pulp subjected to the mineral separation ball milling process to form iron concentrate and circulating water;

adding the iron ore concentrate into the ore material, and carrying out the step of feeding and screening the ore material to separate the ore material into an oversize material and an undersize material;

And introducing the circulating water into the first cyclone and/or the second cyclone for recycling.

2. The method for producing blast furnace return ore fine grinding according to claim 1, wherein the ore dressing ball milling process comprises: carrying out primary grinding treatment on the undersize material through a first ball mill to form first ore pulp;

classifying the first ore pulp through a first cyclone;

Returning the underflow of the first cyclone to the first ball mill for secondary grinding treatment;

and (3) performing a concentration and filtration process on the overflow of the first cyclone to prepare the iron concentrate.

3. The method for producing fine blast furnace return ore grinding according to claim 1, wherein in the ore dressing and ball milling process, the ore grinding work index is set to 35 kW-h/t.

4. The method for producing fine blast furnace return ore grinding according to claim 1, wherein in the ore dressing and ball milling process, a long barrel mill is used for the ball mill, and the length is more than 7 m.

5. The method for producing fine blast furnace return ore grinding according to claim 1, wherein in the ore dressing and ball milling process, the cone of the cyclone is less than 20 degrees.