CN109772575B

CN109772575B - Coarse sand selecting and separating mineral processing technology

Info

Publication number: CN109772575B
Application number: CN201910060984.5A
Authority: CN
Inventors: 喻连香
Original assignee: Guangdong Institute of Resources Comprehensive Utilization
Current assignee: Institute of Resource Utilization and Rare Earth Development of Guangdong Academy of Sciences
Priority date: 2019-01-23
Filing date: 2019-01-23
Publication date: 2021-01-08
Anticipated expiration: 2039-01-23
Also published as: CN109772575A

Abstract

The invention discloses a coarse sand selecting and separating beneficiation process, which comprises the following steps: step 1, recycling easy-to-magnetic iron from the crude sand by wet low-intensity magnetic separation to obtain magnetite concentrate and low-intensity non-magnetic substances; step 2, drying the weak-magnetic nonmagnetic substance, and then carrying out mineral grouping by using dry magnetic separation to obtain a mixture of titanium rough concentrate, rare earth and zirconium rough concentrate; step 3, carrying out reduction roasting on the titanium rough concentrate, and then carrying out low intensity magnetic separation to obtain titanium concentrate and titanium-rich magnetite concentrate; performing dry magnetic separation on the mixture of the rare earth and the rough zirconium concentrate to obtain rare earth concentrate and rough zirconium concentrate; and 4, separating the rough zirconium concentrate into rutile concentrate through electro-separation, and then obtaining zirconium concentrate and tailings through gravity separation by a table concentrator. The process of the invention is a dressing-smelting combined flow of wet-type low-intensity magnetic separation, dry magnetic separation, electric separation, gravity separation and reduction roasting, solves the key problem that ilmenite, hematite, titanium-rich hematite and magnetic gangue in the crude sand are difficult to separate, and simultaneously, other useful minerals in the crude sand can be efficiently separated, so that the crude sand resource can be fully utilized.

Description

Coarse sand selecting and separating mineral processing technology

Technical Field

The invention belongs to the technical field of ore dressing, and particularly relates to a coarse sand fine-selection separation ore dressing process.

Background

The process mineralogy research mainly carries out chemical analysis, titanium phase analysis, mineral composition and content measurement, main mineral granularity measurement, mineralogy characteristics and mineral magnetism analysis on the crude sand, and valuable metal occurrence state research. The research of the process mineralogy shows that: the useful minerals recoverable from the crude sand mainly comprise various titanium minerals, magnetite and zircon, and meanwhile, rutile and monazite can be comprehensively recovered. The compositions of minerals in the crude sand are very complex, and besides various titanium-containing minerals with different magnetic strengths and large magnetic variation ranges, the crude sand also contains hematite, titanium-rich hematite, magnetic gangue garnet and amphibole which are overlapped with the magnetic intervals of the titanium minerals. The ilmenite is difficult to be effectively separated from other minerals only by a single magnetic separation method, an electric separation method or a flotation method, and the effective separation of the titaniferous minerals is the key point of the selection and separation process of the crude sand.

The present invention has been made in view of these features.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects of the prior art, provides a coarse sand concentration and separation beneficiation process, and adopts the technical scheme that the basic concept is as follows:

a raw sand fine-selecting separation ore-dressing process comprises the following steps:

step 1, recycling easy-to-magnetic iron from the crude sand by wet low-intensity magnetic separation to obtain magnetite concentrate and low-intensity non-magnetic substances;

step 2, drying the weak-magnetic nonmagnetic substance, and then carrying out mineral grouping by using dry magnetic separation to obtain a mixture of titanium rough concentrate, rare earth and zirconium rough concentrate;

step 3, carrying out reduction roasting on the titanium rough concentrate, and then carrying out low intensity magnetic separation to obtain titanium concentrate and titanium-rich magnetite concentrate; performing dry magnetic separation on the mixture of the rare earth and the rough zirconium concentrate to obtain rare earth concentrate and rough zirconium concentrate;

and 4, separating the rough zirconium concentrate into rutile concentrate through electro-separation, and then obtaining zirconium concentrate and tailings through gravity separation by a table concentrator.

Further, the step 1 is as follows: and recovering the magnetic iron easy to be magnetized from the crude sand by wet low-intensity magnetic separation, and performing wet low-intensity magnetic separation twice to obtain magnetite concentrate and low-intensity non-magnetic substances, wherein the magnetic field intensity of the wet low-intensity magnetic separation twice is 0.15T and 0.45T respectively.

Further, the magnetic field intensity of the dry magnetic separation in the step 2 is 0.4T.

Further, the step 3 comprises:

step 31, carrying out dry magnetic separation on the titanium rough concentrate to separate rare earth rough concentrate, and then carrying out reduction roasting and low-intensity magnetic separation to obtain titanium concentrate and titanium-rich magnetite concentrate;

step 32, performing dry magnetic separation on the mixture of the rare earth and the rough zirconium concentrate to obtain rough rare earth concentrate and rough zirconium concentrate;

and step 33, combining the rare earth rough concentrate obtained in the step 31 with the rare earth rough concentrate obtained in the step 32, separating titanium rough concentrate from the mixture through electric separation, and then obtaining rare earth middling, rare earth concentrate and tailings through dry magnetic separation.

Further, the magnetic field intensity of the dry magnetic separation in the step 31 is 0.3T; the weak magnetic separation is wet weak magnetic separation, and the magnetic field intensity is 0.15T.

Further, in the step 31, 5% of carbon powder is added in the process of reduction roasting, the roasting temperature is 800-.

Further, the magnetic field intensity of the dry magnetic separation in the step 32 is 1.1T; in the step 33, the electric separation is performed twice, the voltage of the electric separation is 22KV and 14KV respectively, the dry-type magnetic separation time is 3 times, and the magnetic field strength is 0.5T, 0.65T and 0.65T respectively.

Further, the step 4 is: and (3) separating conductive products and non-conductive products from the rough zirconium concentrate through primary electric separation, performing secondary electric separation on the conductive products to obtain rutile concentrate and zirconium concentrate, and performing tertiary table reselection on the non-conductive products to obtain zirconium concentrate and tailings.

Further, the voltage of the first time of electric selection is 2KV, and the voltage of the second time of electric selection is 14 KV.

After the technical scheme is adopted, compared with the prior art, the invention has the following beneficial effects.

The process of the invention is a combined flow of wet low-intensity magnetic separation, dry magnetic separation (-reduction roasting-wet low-intensity magnetic separation), electric separation and gravity separation, different separation modes are adopted aiming at different mineral properties, so that each useful mineral in the hair sand is effectively separated, and the dry magnetic separation (-electric separation) -reduction roasting-wet magnetic separation smelting combined flow is adopted to effectively separate the hematite, magnetic gangue garnet and hornblende which easily enter titanium concentrate by utilizing the characteristics that the magnetism of the hematite and the hematite rich in titanium is enhanced after reduction roasting and the electric property between the magnetic gangue and the titanium mineral is poor; the method solves the key problem that titanium in the coarse sand is difficult to purify, obtains qualified titanium concentrate, and simultaneously can efficiently separate other useful minerals in the coarse sand, so that the coarse sand resource can be fully utilized.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention to its proper form. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

FIG. 1 is a schematic diagram of a process principle of selection and separation of crude sand in the embodiment of the invention;

FIG. 2 is a magnetic grouping test procedure of a dry magnetic separation useful mineral in an embodiment of the present invention;

FIG. 3 is a flow chart of a rare earth rough concentrate concentration separation test in the embodiment of the invention;

FIG. 4 is a flow chart of a titanium rough concentrate concentration separation test in an embodiment of the invention;

FIG. 5 is a flow chart of a separation test for concentration of zirconium rough concentrate in an embodiment of the present invention;

FIG. 6 is a process flow of a full-flow beneficiation test for fine separation of coarse sand in the embodiment of the present invention;

FIG. 7 is a quality flow of a whole-flow beneficiation test for fine separation of coarse sand in the embodiment of the present invention;

FIG. 8 is a recommended process flow of the selection and separation of the crude sand and the mineral separation production in the embodiment of the invention.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used for illustrating the present invention and are not intended to limit the scope of the present invention.

Examples

1. Test specimen

The test ore sample of the test is taken from a Ma La Jila mine area of the republic of Ma La Vietnam in Africa, about 440kg of the test gross sand sample is divided into 11 bags, each bag is about 40kg, the bag number is 1-11, the 11 bags of gross sand are all mixed together, and after being uniformly mixed, the mixture is divided into a plurality of samples through a riffle for a plurality of times.

2. Analysis of samples

The composition of the elements of the crude sand is qualitatively detected by adopting X fluorescence, the result is shown in a table 2-1, and the content of the main elements is quantitatively detected by adopting a chemical analysis method, and the result is shown in a table 2-2.

TABLE 2-1 results of semi-quantitative analysis of X-ray fluorescence spectra of the crude sands

Element(s)	ZrO₂	HfO₂	TiO₂	Fe₂O₃	ZnO	MnO	Nb₂O₅
								Content%	1.307	0.066	26.544	51.219	0.018	0.926	0.033
Element(s)	Na₂O	K₂O	SiO₂	Al₂O₃	MgO	CaO	P₂O₅
								Content%	0.144	0.081	14.004	2.894	1.284	0.934	0.283
Element(s)	SO₃	Cr₂O₃	Sc₂O₃	CeO₂	ThO₂	Y₂O₃	Cl
								Content%	0.024	0.059	0.013	0.117	0.016	0.011	0.023

From the analysis results in Table 2-1, it is found that the useful elements contained in the sample in a large amount include titanium and iron, and further, zirconium and a small amount of rare earth.

TABLE 2-2 Multi-element analysis results of the grit chemistry

Element(s)	TiO₂	Zr(Hf)O₂	REO	Nb₂O₅	Fe
						Content%	29.43	1.70	0.106	0.036	39.82
Element(s)	P₂O₅	Al₂O₃	CaO	MgO	MnO
						Content%	0.06	2.73	0.35	2.12	0.39
Element(s)	SiO₂	K₂O	Na₂O	CeO₂	Sc
						Content%	12.57	0.038	0.067	0.036	0.008

The results of the multi-element analysis of the sand chemistry show that zirconium (hafnium) and associated beneficial elements, namely rare earth can be comprehensively utilized besides titanium and iron in the sand; the content of other useful elements is trace, and the comprehensive recovery value is not high. Titanium, iron, zirconium and rare earth are target elements comprehensively recovered in the test.

Titanium phase analysis was performed on the sand wool, and the results are shown in tables 2 to 3.

TABLE 2-3 titanium phase analysis results of the grit

The titanium phase analysis result shows that the occurrence state of titanium is complex, and the titanium exists mainly in the form of ilmenite, secondly in the forms of iron-rich ilmenite, titanium-rich hematite and titanium silicate, and a small amount of titanium exists in the magnetic iron, or in the forms of rutile and leucolite.

MLA mineral automatic quantitative detection equipment is adopted, and the results are shown in tables 2-4 when the mineral quantitative detection is carried out on the gross sand by combining with microscope identification. As can be seen from tables 2-4, in the present sample, the iron and titanium minerals are very complex, and the iron minerals include magnetite, titanomagnetite, maghemite, hematite rich in titanium, hematite and a small amount of limonite; the titanium minerals are mainly ilmenite, and then iron-rich ilmenite, and a small amount of titanic hematite, rutile, leucoxene and sphene; the zirconium mineral is zircon and trace baddeleyite; the rare earth minerals are mainly monazite and a small amount of xenotime; the gangue minerals are few in quantity and many in types, mainly comprise garnet, hornblende and quartz, and secondly comprise pyroxene, feldspar, kyanite, apatite and the like.

TABLE 2-4 quantitative determination of gross sand minerals

MLA measures the particle size distribution of each valuable mineral in the crude sand, and the results are shown in tables 2-5. According to the particle size distribution result of the main valuable minerals, the particle sizes of the valuable minerals in the sample are close, the particle size range is narrow, the particle size distribution result is mainly concentrated on the particle size fraction of 0.045-0.30 mm, the particle size fraction belongs to the easily selected particle size fraction of gravity separation and magnetic separation, only the particle size of the titanium white is slightly finer, the occupancy rate of the particle size fraction smaller than 0.045mm reaches more than 30%, the gravity separation recovery has certain influence, but the quantity of the titanium white is small, and the influence on the total titanium recovery rate is small.

TABLE 2-5 grit size distribution of major valuable minerals in the grit

3. Mineral processing technology

The equipment mainly used in the test is shown in Table 3-1.

TABLE 3-1 Equipment used mainly for the test

According to the mineral characteristics, the magnetic iron which is easy to be magnetized can be recovered by adopting wet low-intensity magnetic separation; drying the weak-magnetic nonmagnetic substances, and then performing mineral grouping by adopting dry magnetic separation to obtain titanium rough concentrate, rare earth rough concentrate and zirconium rough concentrate; the titanium rough concentrate is subjected to reduction roasting to strengthen the magnetism of hematite which is difficult to separate from titanium and hematite rich in titanium, and then qualified titanium concentrate and secondary iron concentrate rich in titanium can be obtained through low-intensity magnetic separation; separating the non-magnetic ilmenite and the magnetic gangue from the rare earth rough concentrate by adopting a dry magnetic-electric separation combined process to obtain rare earth concentrate; separating the rough zirconium concentrate into rutile concentrate by electric separation, and performing gravity separation on a non-conducting product by a table concentrator to remove most of gangue to obtain zirconium concentrates with different qualities. Therefore, the process principle of the coarse sand concentration separation beneficiation process established in the test is a combined process of wet low-intensity magnetic separation, dry magnetic separation (-reduction roasting-wet low-intensity magnetic separation), electric separation and gravity separation (see figure 1).

The examination of the occurrence state of iron shows that the iron in the form of magnetic iron mineral in the gross sand accounts for 27.16 percent of the total iron content, and the part has strong ferromagnetism and is easy to carry out magnetic separation and can be recovered by wet type low intensity magnetic separation. The occurrence state of strong magnetic iron in the crude sand is complex, strong magnetic iron minerals comprise magnetite, titanomagnetite, maghemite and the like, the iron content in various iron minerals is different, the iron minerals can be subdivided through rough concentration, scavenging and selection, the iron minerals are not the key points of the embodiment, the separation is also a mature process, and the description is omitted.

The weak magnetic tailings from which magnetite is separated contains a large amount of useful minerals such as ilmenite, iron-rich ilmenite, titanium-rich hematite, small amount of white titanium ore, rare earth minerals, zircon, rutile and the like, magnetic gangue such as garnet and amphibole and small amount of quartz, pyroxene, feldspar, kyanite, apatite and the like. In order to ensure the stability of the ore sample in each test of dry magnetic separation, the magnetic separation condition optimized by low-intensity magnetic separation is adopted: the roughing magnetic field intensity is 0.15T, the scavenging magnetic field intensity is 0.45T, the production of dry magnetic separation flotation test samples is carried out, and the test results are shown in a table 3-2. In the following dry magnetic separation, the non-magnetic material subjected to low-intensity magnetic separation is used as an ore feeding sample in each test.

TABLE 3-2 production test results of dry magnetic separation selection test sample

The method comprises the steps of separating various magnetic minerals in nonmagnetic objects subjected to low-intensity magnetic separation into titanium rough concentrate 1, rare earth rough concentrate and zirconium rough concentrate under different magnetic field conditions according to the magnetic differences, and then separately concentrating each rough concentrate. Because the magnetic intervals of the hematite, the garnet and the hornblende are the same as those of titanium minerals, pure titanium concentrate cannot be obtained through wet high-gradient magnetic separation in an exploration test, and the aims of obtaining a part of titanium concentrate in advance and reducing the dry magnetic separation amount are fulfilled. Therefore, the magnetic grouping of the useful minerals is directly carried out by dry magnetic separation, the test flow of the magnetic grouping of the useful minerals is shown in figure 2, and the test results are shown in tables 3-3.

TABLE 3-3 magnetic grouping test results of useful minerals for dry magnetic separation

Weak magnetismSelecting non-magnetic material under 0.4T magnetic field condition, performing once roughing, and selecting under 0.3T magnetic field condition to obtain TiO-containing material₂42.55% of titanium rough concentrate, wherein ZrO₂The content is 0.04 percent, the REO content is 0.04 percent, the content is less, but the titanium grade is influenced by more hematite contained in the titanium rough concentrate; separating nonmagnetic material selected under dry magnetic field condition of 0.4T under magnetic field condition of 1.1T again to separate zircon, rutile, gangue, monazite, titanium mineral and magnetic gangue mineral, wherein the 1.1T nonmagnetic material is zirconium rough concentrate, wherein ZrO is ZrO₂26.24% of REO, 0.07% of TiO₂The content is 5.09%, and the zirconium grade is influenced by more gangue; combining 0.3T non-magnetic material and 1.1T magnetic material to obtain rare earth rough concentrate with REO content of 0.4%, ZrO₂0.09% of TiO₂The content is 20.99 percent, and the grade of rare earth is mainly influenced by titanium minerals, garnet and amphibole.

The yield of the rare earth rough concentrate obtained by dry magnetic separation within the magnetic field intensity range of 0.3-1.1T relative to the raw ore is 18.84%, wherein the content of REO is 0.40%, the minerals mainly comprise monazite, various titanium minerals and hematite, a small amount of zircon and rutile are mixed, and the magnetic gangue mainly comprises garnet and hornblende. According to the electrical property difference between the titanium mineral and other minerals in the rare earth rough concentrate, firstly, electrically separating the titanium mineral from the rare earth rough concentrate, wherein the conductor part is titanium rough concentrate 2; and separating most of magnetic gangue garnet and hornblende from the rare earth rough concentrate by dry magnetic separation to obtain the rare earth concentrate. The rare earth rough concentrate concentration and separation test flow is shown in figure 3, and the test results are shown in tables 3-4.

TABLE 3-4 RE Rough concentrate concentration separation test results

The test results in tables 3-4 show that the rare earth rough concentrate can separate most of titanium minerals under the condition of 22KV electric field, non-conducting products can separate purer garnets under the condition of 0.5T magnetic field, and further fine separation can separate a small amount of titanium minerals which are difficult to be magnetized and a small amount of magnetic gangue (garnets and hornblendes) under the condition of 0.65T magnetic field intensity, and finally rare earth concentrate with 63.16% of REO content and 58.99% of relative raw ore recovery rate can be obtained. Titanium rough concentrate 2 generated in the rare earth concentration process and titanium rough concentrate 1 obtained in the grouping of magnetic substances obtained in the dry magnetic separation process are combined together to be subjected to reduction roasting process, and a part of obtained titanium middling and rare earth middling can be stockpiled for further treatment in later production.

The main minerals in the titanium rough concentrate comprise ilmenite, iron-rich ilmenite, hematite and titanium-rich hematite, the magnetism, the electrical property, the density and the floatability of the minerals are all similar, and the minerals are difficult to be effectively separated by magnetic separation, electric separation, gravity separation and flotation methods. How to effectively separate the hematite is one of the difficulties in the current mineral separation technology, the hematite and the hematite rich in titanium can be roasted under the reducing condition to increase the magnetism, and the reaction formula is as follows:

therefore, the research adopts a combined flow of reduction roasting and wet type low intensity magnetic separation dressing and smelting to treat the titanium rough concentrate so as to achieve the purpose of improving the grade of the ilmenite.

The titanium rough concentrate 1 and the titanium rough concentrate 2 obtained in the previous flow are merged and then enter the reduction roasting operation, the yield of the titanium rough concentrate entering the furnace is 63.15 percent, and TiO is added₂43.07% of Fe content and 92.41% of titanium recovery rate, wherein the Fe content is 41.47% and ZrO content is₂The content is 0.04 percent and the REO content is 0.039 percent. The titanium rough concentrate concentration and separation test flow is shown in figure 4, and the test results are shown in tables 3-5.

Tables 3-5 titanium Rough concentrate concentration separation test results

The temperature of solid carbon reduction roasting adopted in a hematite test room is generally between 800 and 900 ℃, the roasting time is generally between 10 and 20min, and the consumption of the reduced carbon powder is generally between 3 and 5 percent. The test is carried out by reducing roasting in a muffle furnace under the conditions of a roasting temperature of 875 ℃, a roasting time of 17min and 5 percent of carbon powder, wherein a drum magnetic separator is adopted for wet low-intensity magnetic separation, and the magnetic field intensity is 0.15T.

The test results in tables 3-5 show that the titanium rough concentrate after reduction roasting can be effectively separated by wet low-intensity magnetic separation, the grade of the titanium concentrate can be improved from 43.07 percent to 49.17 percent, the titanium recovery rate is 66.36 percent relative to the raw ore, the recovery rate of the recyclable titanium raw ore in the sand is 80.89 percent (the theoretical recovery rate of titanium is about 82.04 percent), and the titanium-containing ore is better recovered. Meanwhile, the titanium-rich secondary iron ore concentrate (Fe 49.32%, TiO) with higher titanium content and 29.02% of the recovery rate of the iron relative to the raw ore can be comprehensively recovered₂32.72％)

Coarse zirconium ore (non-magnetic material) separated by dry magnetic separation under the condition of 1.1T magnetic field is mainly zircon mineral, then rutile mineral, gangue mineral mainly quartz and feldspar, and then small amount of kyanite, apatite and pyroxene. According to the electric property difference between rutile and other minerals, rutile can be separated from zircon and gangue minerals by electric separation, and then according to the density difference between non-conductive products, the zircon and gangue minerals can be separated by gravity separation table. The test flow of the concentration and separation of the rough zirconium concentrate is shown in figure 5, and the test results are shown in tables 3-6.

TABLE 3-6 results of the separation test for the concentration of coarse zirconium concentrate

The results of the electric separation-reselection tests in tables 3-6 show that TiO can be obtained under the condition of 16KV electric field by one-time rough separation and one-time fine separation of the zirconium rough concentrate through the electric separation process₂Rutile with 77.86% content and titanium recovery of 0.92% (rutile mineral recovery of 91.09%)Stone concentrate; ZrO can be obtained in the electric field range of 16-22 KV₂The zirconium rough concentrate 1 with the content of 55.79 percent and the zirconium recovery rate of 12.47 percent also contains a small amount of rutile and trace gangue in the zirconium concentrate 1.

And (3) reselecting and discarding the tailings of the non-conducting products sorted under the condition of a 22KV electric field by adopting a table concentrator, discarding gangue with the operation yield of 52.55% (3.29% relative to the recovery rate of the raw ore), and discarding the tailings by adopting the table concentrator for three times to obtain two zirconium concentrates with different grades: zirconium concentrate 2 (ZrO)₂65.04% and the recovery rate of Zr is 42.85%, wherein the TiO content is₂0.82%); zirconium concentrate 3 (ZrO)₂The content of TiO in the zirconium is 60.78 percent, the recovery rate of zirconium is 33.96 percent₂0.79%); and a zirconium middling (ZrO)₂The content of TiO in the zirconium is 40.50 percent, the recovery rate of zirconium is 4.05 percent₂0.45 percent) of zirconium middlings produced in future production can be returned to the middling recleaning table for recleaning again so as to further improve the recovery rate of zirconium.

The recovery rate of the three zirconium concentrates combined zirconium is 89.28%, and the zirconium in the crude sand is effectively recovered.

The technological process of the full-flow beneficiation test for fine selection and separation of the coarse sand is shown in a figure 6, the full-flow number and quality process is shown in a figure 7, and the final product sorting indexes of the full-flow test are shown in tables 3-7.

TABLE 3-7 Final product selection index for full-flow test

4. Product analysis

Firstly, magnetite concentrate: yield 18.61%, Fe content 61.68%, TiO₂The content is 6.48 percent, the iron recovery rate is 28.82 percent (the theoretical recovery rate of the magnetite in the crude sand is 27.16 percent), the magnetite in the crude sand is effectively recovered, and meanwhile, a part of titanomagnetite and maghemite are also recovered.

② titanium-rich iron concentrate: fe content of 49.32%, iron recovery rate of 29.02%, wherein TiO₂The content was 32.72%. Fe + TiO₂The content is more than 80 percent, and the product can be directly sold.

③ titaniumAnd (3) concentrate: yield 39.72% TiO₂The content of the titanium ore is 49.17 percent, the titanium recovery rate is 66.36 percent (the titanium recovery rate relative to the coarse sand is 82.04 percent), the titanium ore is effectively recovered, and the unrecovered titanium is mainly contained in the titanium-rich hypoferrite concentrate separated by magnetic separation after the reduction roasting.

The following products are also effectively and comprehensively recovered:

fourthly, three zirconium concentrates with different times are obtained: zirconium concentrate 1 (ZrO)₂55.79% and the recovery rate of Zr is 12.47%, wherein the TiO content is₂4.56%); zirconium concentrate 2 (ZrO)₂65.04% and the recovery rate of Zr is 42.85%, wherein the TiO content is₂0.82%); zirconium concentrate 3 (ZrO)₂The content of TiO in the zirconium is 60.78 percent, the recovery rate of zirconium is 33.96 percent₂0.79%); the recovery rate of the three zirconium concentrates combined zirconium is 89.28%, and the zirconium in the crude sand is effectively recovered.

Fifth, rutile concentrate: TiO 2₂The ZrO content was 77.86%, the titanium recovery rate was 0.92% (relative to the recovery rate of rutile in the raw ore, 91.09%)₂2.34％；

Sixthly, rare earth concentrate: the REO content is 63.16 percent, the recovery rate is 58.99 percent, and the TiO content in the product₂1.43% and contains ZrO₂0.18％；

Titanium concentrate 1 obtained by dry magnetic separator under 0.3T magnetic field condition, wherein the titanium concentrate contains TiO₂42.55 percent and the titanium content does not reach the product requirement of 48 percent. Separating the magnetic substance by a dry magnetic separator under the condition of 0.3T-1.1T magnetic field, and separating the conductive product under the condition of 14KV electric field to obtain titanium concentrate 2 containing TiO₂47.33 percent and the titanium content does not reach the product requirement of 48 percent. Through quantitative detection and analysis of the titanium concentrate 1 and the titanium concentrate 2, the grade of the titanium concentrate is difficult to improve due to the existence of hematite and titanium-rich hematite. The magnetism and floatability of hematite and titanium-rich hematite are similar to those of ilmenite, and the grade of the titanium concentrate can be improved only by adopting a reduction roasting method to reduce hematite and titanium-rich hematite to strengthen the magnetism of the hematite and the titanium-rich hematite and then separating the hematite and the ilmenite by adopting weak magnetic separation.

Because the content of rutile and monazite in the crude sand is less, the grade is not high during the concentration and separation, and the crude sand is greenDuring production, 16KV can be reduced to 14KV when rutile is selected on the basis of a test; during dry magnetic separation operation, once scavenging is added after titanium roughing (under the condition of a 0.4T magnetic field); when the rare earth is subjected to dry magnetic separation, one-time separation (0.65T magnetic field intensity) is added; thereby obtaining purer rutile concentrate and rare earth concentrate. High zirconium content (ZrO) in zirconium middlings₂40.50 percent), the zirconium middling can be returned to the middling and then separated again in the shaking flow in the production, so as to further improve the recovery rate of zirconium. The recommended flow of the coarse sand concentration separation beneficiation production is shown in a figure 8.

The process flow of the embodiment is a combined flow of wet low-intensity magnetic separation-dry magnetic separation (-reduction roasting-wet low-intensity magnetic separation) -electric separation-reselection, the process has no medicament pollution, and tail water generated in the later production can be completely recycled. The raw sand is treated by the raw sand selecting, dressing and separating process, so that useful minerals such as magnetite, titanomagnetite, maghemite, ilmenite, iron-rich ilmenite, titanium-rich hematite, zirconite, rutile and monazite in the raw sand can be effectively utilized, and the raw sand resource can be effectively utilized.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The process for selecting, separating and concentrating the crude sand is characterized by comprising the following steps of:

2. The process for selecting, separating and concentrating coarse sand according to claim 1, wherein the step 1 is as follows: and recovering the magnetic iron easy to be magnetized from the crude sand by wet low-intensity magnetic separation, and performing wet low-intensity magnetic separation twice to obtain magnetite concentrate and low-intensity non-magnetic substances, wherein the magnetic field intensity of the wet low-intensity magnetic separation twice is 0.15T and 0.45T respectively.

3. The process of claim 1, wherein the magnetic field strength of the dry magnetic separation in the step 2 is 0.4T.

4. The process of claim 1, wherein the step 3 comprises:

5. The process of claim 4, wherein the magnetic field strength of the dry magnetic separation in the step 31 is 0.3T; the weak magnetic separation is wet weak magnetic separation, and the magnetic field intensity is 0.15T.

6. The process of claim 4, wherein in the step 31, 5% of carbon powder is added during the reduction roasting at 800-900 ℃ for 15-20 min.

7. The process of claim 4, wherein the magnetic field strength of the dry magnetic separation in step 32 is 1.1T; in the step 33, the electric separation is performed twice, the voltage of the electric separation is 22KV and 14KV respectively, the dry-type magnetic separation time is 3 times, and the magnetic field strength is 0.5T, 0.65T and 0.65T respectively.

8. The process of wool sand concentration and separation beneficiation process according to claim 1, wherein the step 4 is: and (3) separating conductive products and non-conductive products from the rough zirconium concentrate through primary electric separation, performing secondary electric separation on the conductive products to obtain rutile concentrate and zirconium concentrate, and performing tertiary table reselection on the non-conductive products to obtain zirconium concentrate and tailings.

9. The process according to claim 8, wherein the voltage of the first electric separation is 2KV, and the voltage of the second electric separation is 14 KV.