CN101862703B - Separation-smelting combined method for producing iron ore concentrate from oolitic lean hematite - Google Patents

Abstract

The invention relates to a separation-smelting combined method for producing iron ore concentrate from oolitic lean hematite. The technical scheme first comminutes oolitic lean hematite containing 30 to 40 percent of iron, the comminuted mineral slurry enters a high-intensity magnetic separator and preseparated, weak-magnetic mineral is turned into strong-magnetic concentrate, and tailings are removed in advance; the strong-magnetic concentrate is mixed with pulverized coal, the weight of which accounts for 10 to 30 percent of the weight of the concentrate, and the mixture is heated to 900 DEG C to 1100 DEG C in a muffle furnace, and is magnetically roasted as the temperature is kept for 1 to 3 hours; after being cooled, the magnetically roasted mineral sample is wet-milled, and is then fed into a low-intensity magnetic separator and separated under low-intensity magnetism, magnetic mineral is turned into weak-magnetic concentrate, and thereby high-quality iron concentrate is produced. The grade of the obtained iron concentrate is higher than 64 percent, the phosphor content is less than 0.15 percent, and the sulfur content is less than 0.10 percent. The invention is characterized by simple process flow, good technical and economic indexes and high product quality.

Description

A kind of roe shape lean hematite is produced the selecting smelting combination method of iron ore concentrate

Technical field

The present invention relates to the method for a kind of ore dressing and metallurgical associating, particularly relate to the selecting smelting combination method that a kind of roe shape lean hematite is produced iron ore concentrate.

Background technology

Iron is to find in the world the earliest, utilizes the extensivelyst, and a kind of metallic element that consumption is maximum, its consumption account for about 95% of metal total flow.Iron extracts from iron ore, and bloodstone and magnetic iron ore all are common iron ores.Oolitic hematite is a kind of of bloodstone, mainly is distributed in the ground such as Hubei, Hunan and Guizhou of China, and its reserves account for about 1/3 of China's bloodstone reserves, account for about 1/9 of iron ore deposit gross reserves.But the oolitic hematite disseminated grain size is superfine; And frequent and siderite, chamosite and phosphorus ore containing symbiosis or mutual parcel; Therefore oolitic hematite is one of iron ore type of the most difficult choosing of generally acknowledging both at home and abroad at present, because its difficult choosing causes the type iron ore deposit not obtain basically utilizing.Along with the high speed development of China's steel and iron industry, the poor iron ore reserves of high-grad iron ore deposit and Yi Xuan are exhausted day by day, thereby the new method that research and development are produced iron ore concentrate with roe shape lean hematite has great importance.

The research of oolitic hematite both at home and abroad comprises: dephosphorization, desiliconization, desulfurization, reverse flotation, selectivity are gathered group-reverse flotation, high-gradient magnetic separation, direct-reduction process, acidleach, chloridising roasting-acid leaching process etc.But, the report of its successful enrichment but seldom [Zhang Jin is auspicious, Hu Li can wait. difficulty is selected the research and utilization present situation and the prospect of oolitic hematite, Chinese Mining Industry, 2007,16 (7): 74-76].

Wang Yanmin etc. are to the mineral composition of Guangxi village autumn oolitic hematite and the characteristics of institute's adopting process flow process at present, carried out magnetic matrix, background field intensity, have given the ore deposit flow velocity and than tests such as magnetic loading amounts.Reach a conclusion and be: 1. high-gradient magnetic method can effectively sort the thin mud of the strong magnetic tail of village autumn oolitic hematite that contains the micro-size fraction iron mineral; 2. the structural parameters of magnetic matrix net, background field intensity, give the ore deposit flow rate and than magnetic loading, the influence that the sample High-gradient Magnetic is separated index the most obviously [Wang Yanmin, Li Mingde. the high-gradient magnetic separation of oolitic hematite. Mineral Engineering, 1986,6 (8): 38-40].

Wang Jing etc. adopt quadrature float test method, have investigated the major influence factors of Hezhang, Guizhou oolitic hematite flotation, reach a conclusion at last: the 1. suitable ore grinding time, extremely important to the flotation of oolitic hematite; 2. to make collecting agent obvious to the enrichment of iron ore concentrate for lauryl amine; But its foam is unusual abundant and stable very big to scraping the influence of bubble and subsequent job; So, select suitable adjustment agent to eliminate the harmful effect of bubble, will be that the emphasis that from now on oolitic hematite is carried out flotation research is dealt with problems; 3. used dosing is bigger, reduces dosing and selects medicament more efficiently, be from now on striving direction [Wang Jing, Shang Yanbo open deep. oolitic hematite flotation experiment Primary Study. Mineral Engineering, 2004,24 (3): 38-40].

Statement literary composition etc. adopts fixed bed process and fluidized bed method; Heating has been carried out direct reduction magnetic separation test with outer heating to Hezhang, Guizhou oolitic hematite in comprising; And test of the rotary kiln for directly reducing of semi-industrial scale and rotary kiln model test, process has been carried out thermodynamic analysis.Reach a conclusion at last: 1. oolitic hematite directly reduces, and the heating rotary kiln is for well beyond the reduction apparatus; 2. anthracite is made reducing agent reduction oolitic hematite, and its performance is good than bituminous coal; 3. adopt fixed bed or heat rotary kiln outward oolitic hematite is directly reduced; Also original product carries out the low intensity magnetic separation separation, can obtain to separate preferably index [statement literary composition, Ceng Yongzhen; Chen Qiping. Hezhang, Guizhou oolitic hematite directly reduces the magnetic separation experimental study. metal mine; 1997, (11): 13-16,3].

End is got up, and mainly is divided into two big types to the research method of oolitic hematite, and one type is beneficiating method, mainly comprises flotation and magnetic separation, and another kind of is metallurgy method, like direct reduction, reduction roasting etc.But for the ore of difficult choosing like this, single beneficiating method can not obtain high-grade iron ore concentrate (the iron grade is more than 60%), be feasible and remove impurity such as phosphorus in the ore, sulphur, silicon with floatation, but the grade of flotation iron ore concentrate is difficult to reach requirement; For metallurgy method, no matter be direct reduction, or reduction roasting, as far as poor iron ore, all be difficult to obtain good effect.

Summary of the invention

The present invention is directed to the problem that exists in the present roe shape lean hematite research and development, a kind of ore dressing and the metallurgical new method that combines of producing fine quality iron concentrate from roe shape lean hematite is provided, be beneficial to the development and use of such ore, alleviate the imbalance between supply and demand of iron ore.

Technological process of the present invention may be summarized to be " high magnetic pre-selection-magnetizing roast-weak magnetic separation ", promptly is directed against the roe shape lean hematite of iron content 30%-40%.Concrete grammar is following:

At first carry out the comminution ore deposit; Wet-milling is to-200 order content 75%-85%; Ore pulp behind the ore grinding gets into intensity magnetic separator and under the magnetic field intensity of 700kA/m-1000kA/m, carries out preliminary election, and magnetic mineral gets into strong magnetic concentrate, and non magnetic ore gets into mine tailing; Can throw the 30%-40% that accounts for raw ore except that the weight of mine tailing in advance, concentrate grade can improve 10-15 percentage point than raw ore; Magnetic concentrate mixes with coal dust, and the weight ratio of concentrate and coal dust is 100: 10-100: 30, in Muffle furnace, be heated to 900-1100 ℃, and insulation 1-3h carries out magnetizing roast, makes weak magnetic mineral be converted into strongly magnetic mineral; Sample ore after the magnetizing roast is the ore deposit of regrinding after cooling; Wet-milling accounts for 75%-90% to-200 orders, feeds the low intensity magnetic separation machine after sizing mixing, and under the field intensity of 200kA/m-300kA/m, carries out weak magnetic separation; Magnetic mineral gets into inferior fine magnetite concentrate; Become final product-one-level fine quality iron concentrate, phosphorous, sulphur all meets the requirement of smelting, simultaneously the output weakly magnetic tailings.

Characteristics of the present invention are, technological process is simple, and technical-economic index is good, and product is a fine quality iron concentrate, and ferrous grade is high, and foreign matter of phosphor, sulfur content are low.

Description of drawings

Fig. 1 is a process chart of the present invention.

The specific embodiment

Embodiment 1:

Roe shape lean hematite (primary sample): TFe:31.40%, P:0.12%, S:0.05%, SiO ₂: 23.91%, CaO:5.23%, MgO:1.86%.(quality percentage composition, down together)

At first carry out the comminution ore deposit, wet-milling to-200 order content 79.6%, the ore pulp behind the ore grinding get into intensity magnetic separator and under the magnetic field intensity of 780kA/m, carry out preliminary election, and magnetic mineral gets into strong magnetic concentrate, and non magnetic ore gets into mine tailing, throw in advance and remove mine tailing; Magnetic concentrate mixes with coal dust, and the weight ratio of concentrate and coal dust is 100: 15, in Muffle furnace, is heated to 950 ℃, and insulation 1.5h carries out magnetizing roast; The magnetizing roast sample ore is the ore deposit of regrinding after cooling, and wet-milling accounts for 82.5% to-200 orders, feeds the low intensity magnetic separation machine after sizing mixing, and under the field intensity of 200kA/m, carries out weak magnetic separation, and magnetic mineral entering inferior fine magnetite concentrate becomes final fine quality iron concentrate product.

The present embodiment result is: the high intensity magnetic separation concentrate yield is 64.8%, throws tail 35.2% in advance, and concentrate grade 40.05%, iron recovery are 83.02%; Roasted product iron grade 44.82%, low intensity magnetic separation concentrate yield 29.64%, concentrate contain Fe grade 64.47%, to the raw ore rate of recovery 61.13%.Impurity content is respectively: phosphorous 0.10%, and sulfur-bearing 0.06%, siliceous 8.91%.

Embodiment 2:

Roe shape lean hematite (primary sample): TFe:30.80%, P:0.14%, S:0.08%, SiO2:22.45%, CaO:5.96%, MgO:1.93%.

At first carry out the comminution ore deposit, wet-milling to-200 order content 81.50%, the ore pulp behind the ore grinding get into intensity magnetic separator and under the magnetic field intensity of 820kA/m, carry out preliminary election, and magnetic mineral gets into strong magnetic concentrate, and non magnetic ore gets into mine tailing, throw in advance and remove mine tailing; Magnetic concentrate mixes with coal dust, and the weight ratio of concentrate and coal dust is 100: 20, in Muffle furnace, is heated to 1000 ℃, and insulation 2h carries out magnetizing roast; The magnetizing roast sample ore is the ore deposit of regrinding after cooling, and wet-milling accounts for 84% to-200 orders, feeds the low intensity magnetic separation machine after sizing mixing, and under the field intensity of 230kA/m, carries out weak magnetic separation, and magnetic mineral entering inferior fine magnetite concentrate becomes final fine quality iron concentrate product.

The present embodiment result is: the high intensity magnetic separation concentrate yield is 62.3%, throws tail 37.7% in advance, and concentrate grade 41.26%, iron recovery are 81.88%; Roasted product iron grade 45.91%, low intensity magnetic separation concentrate yield 28.02%, concentrate contain Fe grade 65.24%, to the raw ore rate of recovery 60.09%.Impurity content is respectively: phosphorous 0.12%, and sulfur-bearing 0.09%, siliceous 8.22%.

Claims (4)

1. a roe shape lean hematite is produced the selecting smelting combination method of iron ore concentrate; It is characterized in that the roe shape lean hematite to iron content 30%-40%, at first carry out the comminution ore deposit, wet-milling is to-200 order content 75%-85%; Ore pulp behind the ore grinding gets into intensity magnetic separator and carries out high magnetic pre-selection; Magnetic mineral gets into concentrate, and non magnetic ore gets into mine tailing, throws in advance and removes mine tailing; The high intensity magnetic separation concentrate mixes with coal dust, and magnetizing roast is carried out in heating and insulation in Muffle furnace; Sample ore after the magnetizing roast is the ore deposit of regrinding after cooling, and wet-milling accounts for 75%-90% to-200 orders, feeds the low intensity magnetic separation machine after sizing mixing and carries out weak magnetic separation, and magnetic mineral gets into inferior fine magnetite concentrate, becomes final fine quality iron concentrate product, while output weakly magnetic tailings.

2. roe shape lean hematite according to claim 1 is produced the selecting smelting combination method of iron ore concentrate, it is characterized in that described high magnetic pre-selection magnetic field intensity is 700kA/m-1000kA/m.

3. roe shape lean hematite according to claim 1 is produced the selecting smelting combination method of iron ore concentrate; It is characterized in that the weight ratio that magnetic concentrate mixes with coal dust in the described magnetizing roast operation is 100: 10-100: 30; Sintering temperature is 900-1100 ℃, and temperature retention time is 1-3h.

4. roe shape lean hematite according to claim 1 is produced the selecting smelting combination method of iron ore concentrate, it is characterized in that the magnetic field intensity of the weak magnetic separation behind the described magnetizing roast product ore grinding is 200kA/m-300kA/m.