CN1017420B

CN1017420B - Process for the preparation of ferric oxide powder used for ferrite by utilizing smoke dust of oxygen blast open-hearth furnace

Info

Publication number: CN1017420B
Application number: CN 88105795
Authority: CN
Inventors: 徐建伦; 韩光烈; 刘福球; 吴炳炎; 肖泽勋; 田维强
Original assignee: Xiangtan Iron & Steel Co; METALLURGICAL MATERIAL INST HUNAN PROV
Current assignee: Xiangtan Iron & Steel Co; METALLURGICAL MATERIAL INST HUNAN PROV
Priority date: 1988-10-22
Filing date: 1988-10-22
Publication date: 1992-07-15
Also published as: CN1042134A

Abstract

The present invention relates to a technique for preparing ferric oxide powder for ferrite by using the smoke ash of an oxygen blowing open-hearth furnace, which comprises the following technological processes: the smoke ash is dipped in the waste liquor of hydrochloric acid and diluted sulfuric acid by a hot dipping method, then filtration residue is washed by the industry solution of NaOH, and the filtration residue is filtered, dried, calcined, pulverized, sieved and packed after the filtration residue is washed. The technique has simple process and low cost, ferric oxide powder with over 97% of ferric oxide can be offered, and the ferric oxide powder is suitable for serving as the raw material for the production of ferrite magnetic materials and ferrite magnetic devices; the popularization and the application of the method provide an efficient path for a steel plant for treating smoke pollution and enhancing economic benefit.

Description

Process for the preparation of ferric oxide powder used for ferrite by utilizing smoke dust of oxygen blast open-hearth furnace

The present invention relates to a kind of is that raw material is produced the technology of ferrite with brown iron oxide with the utilizing smoke dust of oxygen blast open-hearth furnace.

Utilizing smoke dust of oxygen blast open-hearth furnace is formed by vapour deposition, and its main thing is ferric oxide mutually, and other Si, Mn, Mg, Ca etc. are respectively 2FeO, SiO ₂, MnO, CaO composite oxides and simple oxide, the about 20um of dust median size, the complete about 2.28m of specific surface area ²/ g, loose density is about 2.023g/cm ³Up to now, this smoke dust is mainly collected by Steel Plant self, returns sintering plant briquetting, sinters piece into for the blast furnace ironmaking utilization.This method is simple, need not increase bulky equipment, and treatment capacity is unrestricted.But because of the smoke dust particle is fine, a part becomes dust again in sintering process, and utilization ratio is low, the repeated contamination environment, and increase steel works sintering dust collecting system load, become comparatively stubborn problem of iron and steel enterprise's environment protection and improvement person.The technology of handling at present the converter dust ash is, with 3～15% hydrochloric acid (0.4～1.8M), or 4-5%(0.5-0.6M) HCL+1-2%(0.15-0.3M) nitric acid, after solution heating (90-100 ℃) processing, washing filtering passes through FeSO then ₄Addition reaction and prepare iron oxide black, this technology simple possible, with low cost, but the purity of the iron oxide black of producing only is about 70%.

The objective of the invention is to make full use of utilizing smoke dust of oxygen blast open-hearth furnace potential advantage, as iron oxide content height, fine particles, characteristics such as specific surface area is big, adopt a series of chemical treatment technologies, improve ferric oxide content in the smoke dust, reduce oxide contents such as silicon, magnesium, calcium, aluminium, phosphorus, produce high purity, be ferric oxide greater than 97% brown iron oxide, thereby improve economic results in society, controling environment to pollute brings benefit to the people.

Technological process of the present invention is described in detail in detail below:

Smoke dust is placed reactor, add the technical hydrochloric acid of 0.5～5 mol or the hydrochloric acid soln and the dilute sulphuric acid waste liquid of each above-mentioned concentration of 50%, in order to leach the impurity in the smoke dust, sulfur acid 6～8 grams per liters in the dilute sulphuric acid waste liquid, the ratio of leach liquor and smoke dust is 1: 1, be that the 1kg smoke dust adds 1 liter of acid solution, heating and constantly stirring then, 40～120 ℃ of insulations down, after 1～5 hour, separate leach liquor, filter residue is after washing, NaOH solution secondary with 0.2～5 mol leaches again, the alkaline solution add-on is 1 liter of NaOH solution of 1kg filter residue, and above-mentioned solution is heated to 40～150 ℃, is incubated 1～5 hour, filtering separation leach liquor then, with the filter residue oven dry, calcined 1 hour ball mill pulverizing down at 600～900 ℃, obtain high purity reddish-brown croci, use the X-ray diffraction analysis, prove that ferric oxide mainly by α-ferric oxide phase composite, can be used as the raw materials for production of ferrite magnetic material.

The principle that technology of the present invention is removed impurity is as follows:

1, removes pasc reaction;

Si in flue dust mainly with 2FeOSiO ₂Or 2CaOSiO ₂Form exist, following reaction takes place in acid, alkali lye:

Reaction (1) product silicic acid is water insoluble, also can condense when being heated to a certain temperature, but in diluted acid, cotton-shaped or precipitation is difficult to separate out, and also can separate with washing, and reaction (2) (3) product water glass water soluble and removing is when producing flocculation H ₂SiO ₃Also can remove by reaction (4).

2, the reaction of manganese

Manganese oxide is a kind of detrimental impurity in permanent-magnet ferrite, but in the Mn-Zn ferrite soft magnetic materials, but is one of chief component, therefore removing it is not complete purpose, see demand and purposes and decide, but in this invented technology, following reaction takes place and is removed in manganese oxide.

Manganous sulfate and Manganous chloride tetrahydrate are all water-soluble.

3, the reaction of magnesium, calcium

It is deliquescence that magnesium oxide is met water at normal temperatures:

Magnesium hydroxide is water insoluble, but is dissolved in acid:

Magnesium chloride and sal epsom are all water-soluble and remove.

Calcium oxide also has hydrolysis reaction to take place, and generates calcium hydroxide, is slightly soluble in hot water, but is dissolved in hydrochloric acid.

When leaching flue dust with hydrochloric acid, magnesium, calcium oxide major part all are removed.

4, the removal of other impurity

Aluminum oxide is dissolved in acid, and following reaction takes place:

The oxide compound of phosphorus generates soluble phosphate in basic solution:

5, the reaction of iron

Ferric oxide is insoluble to alkali, but is dissolved in acid, and following reaction takes place:

In sum, when with acid, when the alkali secondary leaches smoke dust, though ferric oxide can dissolve a part, the also most of dissolving of element oxides such as Si, Mn, Ca, Mg, Al, P, thus the ferric oxide purity of flue dust is improved.

Leach the utilization of waste liquid

When leaching flue dust, remove in the leach liquor and be dissolved with Mn with hydrochloric acid ²⁺, Mg ²⁺, Ca ²⁺, Al ³⁺Outside the plasma, also contain H ₂SiO ₃And Fe ³⁺, particularly add spent pickle liquor itself and just contain 30 grams per liter Fe ²⁺So, contain more Fe in the leach liquor ²⁺, contain certain free acid radical ion in addition, in alkaline leach liquor, remove and contain Na ₂SiO ₃Outward, also remaining has certain free alkali, and these leaching waste liquids all should be reclaimed or handle from material recovery and wastewater discharge standard, and these waste liquids can be used for: (1) produces the pigment iron oxide red, it is refining to leach waste water earlier, produces the pigment iron oxide red with refined wastewater again.(2) be used for wastewater treatment, producing at the ferrite ferric oxide has alkalescence and slightly acidic waste liquid to discharge in the process, and these waste liquids neutralize in wastewater disposal basin, clarify, discharge, and do not need to increase the wastewater treatment expense again.Can be used further to leach the processing flue dust after (3) one times spent picking solution is separated.

Embodiment:

Take by weighing smoke dust 100kg, each 50 liters of the technical hydrochloric acid of adding 0.5～5 mol and dilute sulphuric acid waste liquids are heated to 40～120 ℃, constantly stir, separate leach liquor after 1～5 hour, the washing filter residue, filter residue carries out the secondary leaching for 100 liters with the NaOH solution of 0.2～5 mol again, and heating is incubated 1～5 hour down at 40～150 ℃, filter, separate leach liquor then, with the filter residue oven dry, calcined 1 hour ball mill pulverizing down at 750 ℃, weigh and analyze composition, during it the results are shown in Table 1 ^#Sample.

This technical process is simple, and is with low cost.Add the dilute sulphuric acid waste liquid by present method with hydrochloric acid or hydrochloric acid and leach impurity in the smoke dust, leach SiO with the caustic soda soln secondary ₂Impurity can improve the purity 2.5～4.0% of smoke dust ferric oxide, removes Si35～65%, removes Mn40～60%, and the brown iron oxide of producing contains Fe ₂O ₃＞97%, the raw materials for production that are suitable for doing ferrite magnetic material and device use, and promote the use of present method and can be steelworks and curb environmental pollution, and increase economic efficiency and find an effective way.

Smoke dust leaches table as a result

	Chemical ingredients %						Increase iron rate %	Remove Sl yield %	The rate of recovery % of iron
										Fe ₂O ₃	Sl	Mn	Ca	Mg	Al
	Smoke dust	94.13	0.519	1.53	0.174	0.301										0.1
1 ^＊Sample							97.01	0.24	0.618	0.09	0.13	0.03	3.1	53.8	97.2

Claims

1, a kind of is that raw material is produced the technology of ferrite with brown iron oxide with the utilizing smoke dust of oxygen blast open-hearth furnace, it is characterized in that leaching smoke dust with the technical hydrochloric acid of 0.5～5 mol or the hydrochloric acid soln and the dilute sulphuric acid waste liquid of each above-mentioned concentration of 50%, the add-on of leach liquor adds 1 liter of acid solution for the 1kg smoke dust, with this solution heating and constantly stirring, 40～120 ℃ of insulations down, after 1～5 hour, separate leach liquor, the washing filter residue, again filter residue is placed the NaOH solution of 0.2～5 mol, the alkaline solution consumption adds 1 liter of NaOH solution for the 1kg filter residue, above-mentioned solution is heated to 40～150 ℃, be incubated 1～5 hour, the filtering separation leach liquor is dried filter residue then, calcined 1 hour ball mill pulverizing down at 600～900 ℃.