CN102168172B - A process for extracting and separating boron-iron-magnesium from boron ore - Google Patents

Abstract

A process for extracting and separating boron-iron-magnesium from boron-iron ore, which involves an extraction and separation process of boron, iron and magnesium elements. The process consists of three technical operations: high-temperature roasting of boron-iron ore sulfuric acid leaching process ;Using the process of adding organic solvent to crystallize magnesium salt; acid immersion liquid ferric iron powder reduction and organic solvent crystallization process; the process flow is: roast boronite at a temperature of 700~800 ℃, and then leaching with concentrated sulfuric acid Boronite, after solid-liquid separation, add monohydric alcohol to the acid immersion solution and let it stand, filter to obtain solid MgSO ₄ 7H ₂ O, after the filtrate is reduced and concentrated by positive ferric iron powder or iron filings, add monohydric alcohol and then filter , cooling, crystallization and drying to obtain solid FeSO ₄ •7H ₂ O, and the crystallization liquid contains boric acid. The process of the invention achieves the purpose of extracting and effectively separating boron, iron and magnesium elements, and is suitable for extracting and separating boron, iron and magnesium elements from various iron- and magnesium-containing minerals and industrial waste residues.

Description

A process for extracting and separating boron-iron-magnesium from boron ore

technical field

The invention relates to an extraction and separation process, in particular to a process for extracting and separating boron-iron-magnesium from boronite.

Background technique

At present, the boron resources that can be processed and utilized in our country only account for 10% of the total reserves, which has increasingly prominent contradictions with the needs of the development of the boron industry. The low-grade boron ore in Liaoning, which accounts for 58% of the total reserves of boron resources, is one of the important resources of my country's boron industry. Boronite (B ₂ O ₃ 7.22%, TFe30.0%, MgO24%) is a non-renewable resource. Due to its complex structure, many paragenetic minerals, difficult processing, difficult separation by conventional separation methods and no mature Factors such as processing technology have not been developed and utilized on an industrial scale. The co-extraction of iron-boron-magnesium in symbiotic ores is an important topic with Chinese resource characteristics. At present, there are mainly the following types of comprehensive utilization processes for boron ore, but there are deficiencies in all of them:

1. Mechanical beneficiation

Coarse-grain tailings-stage separation process can be used to separate boronite (B ₂ O ₃ 7.22%, TFe30.0%, MgO24%) with low grade and cannot be directly used as boron chemical raw materials into boron fine powder (B ₂ O ₃ 12%, MgO24%, boron recovery rate 40%) and boron-containing iron powder (B ₂ O ₃ 6.0%, TFe50%, iron recovery rate 90%), the boron recovery rate of the two products together reaches 87% %. According to the research results, the mechanical beneficiation method cannot realize the complete separation of iron and boron, and there is still 47% B ₂ O ₃ present in the boron-containing iron fine powder. The B ₂ O ₃ grade of boron-containing iron fine powder is only 6.0%, which is still a low-grade boron ore, which cannot meet the needs of boron chemical industry.

2. Iron and boron separation technology by fire method

Pyrochemical iron and boron separation technology can obtain boron-rich slag (B ₂ O ₃ 12%, MgO40%) and boron-containing pig iron (B0.6±0.2%), boron is basically not lost, and it is a good solution to boronite Utilization of China Railway Resources. However, the expanded experiment results of 13m ³ blast furnace ironmaking show that the extraction utilization rate of boron and magnesium in this process is still not high.

3. Boronite Wet Separation Technology

Contrary to the separation sequence of the pyrotechnics, the boronite wet separation technology is to extract boron first, and then smelt iron with the residue. This method is also divided into two categories: hydrochloric acid leaching of boronite, organic solvent extraction to extract boron; sulfuric acid leaching of boronite, salting out crystallization of magnesium sulfate monohydrate. The wet separation process is only suitable for processing ores with a B ₂ O ₃ content of more than 10% due to the low grade of the ore and the relative large amount of acid consumption. Because the grades of the boronites that have been found vary greatly, and most of them contain boron Low-grade ore, thus restricting the promotion of wet separation technology research results in the boron industry.

Contents of the invention

The object of the present invention is to provide a kind of technology that extracts and separates boron-iron-magnesium from boron iron ore. The process consists of three technical operations: high-temperature roasting of boron-iron ore and sulfuric acid leaching process, crystallization and separation of magnesium by organic solvent monohydric alcohol, reduction of iron powder in leaching solution and crystallization of ferric sulfate by organic solvent, which realizes the extraction and effective The purpose of separating boron, iron and magnesium elements.

The purpose of the present invention is achieved through the following technical solutions:

A process for extracting and separating boron-iron-magnesium from boron-iron ore, which consists of three technical operations: high-temperature roasting of boron-iron ore and sulfuric acid leaching process; process of crystallizing magnesium salt by adding organic solvent; Valence iron powder reduction and organic solvent crystallization process; the process flow is: roast boronite at 700~800°C, then leach boronite with concentrated sulfuric acid, after solid-liquid separation, add boronite to the acid leaching solution Stand the monohydric alcohol, and filter to obtain solid MgSO ₄ ·7H ₂ O. After the filtrate is reduced and concentrated by positive ferric iron powder or iron filings, add monohydric alcohol, then filter, cool and crystallize and dry to obtain solid FeSO ₄ ·7H ₂ O. The crystallization solution contains boric acid.

The process for extracting and separating boron-iron-magnesium from boronite is described, in which magnetite is converted into hematite during the boronite roasting process.

In the process for extracting and separating boron-iron-magnesium from boron ore, the organic solvent adopts monohydric alcohol for recycling.

Advantage and effect of the present invention are:

1. The invention is a technological method for extracting and effectively separating boron, iron and magnesium elements from boron ore, and integrating three into one. Compared with the prior art, the present invention has a unique processing method, high co-extraction rate of boron, iron and magnesium, simple production process, short process, low equipment investment, less raw material consumption, no waste liquid discharge, easy industrial production, etc. characteristics;

2. According to the different solubility of the inorganic salt in the organic solvent, the step-by-step crystallization under the action of the organic solvent, the products are magnesium sulfate and ferrous sulfate, and the primary separation of the main components in the ore can be realized.

3. The present invention obtains product magnesium sulfate and ferrous sulfate by acid leaching-organic solvent action crystallization method, and product ferrous sulfate is the raw material for preparing high value-added iron products, has characteristics such as high economic value, wide application, product magnesium sulfate It can be directly used to produce magnesium sulfate monohydrate with high value without impurity removal.

4. The organic solvent used in the crystallization process of the present invention can be recycled, which is beneficial to reduce production cost and reduce environmental pollution.

5. The present invention can not only extract and separate the iron and magnesium elements in boronite, but also enrich the boron and silicon elements in boronite, and separate them according to the different physical and chemical properties of the products. Comprehensive utilization of resources;

6. The process enriches the boron in the boronite in the form of boric acid in the crystallization liquid, and can be used to prepare solid boric acid by crystallization.

7. The invention is suitable for extracting and separating boron, iron and magnesium elements from various iron- and magnesium-containing minerals and industrial waste residues, so that various boron ores with different levels of boron content have mining value and avoid waste of resources.

Detailed ways

The present invention will be described in detail below.

The boronite of the present invention converts the magnetite in the ore into hematite through high-temperature roasting, leaches the boronite with sulfuric acid, and after solid-liquid separation, the acid leaching solution is crystallized under the action of monoalcohol to extract magnesium sulfate, and solid-liquid separation is performed again After reduction, the solution is crystallized under the action of monohydric alcohol to prepare ferrous sulfate, and boric acid is mainly enriched in the crystallization solution. The technological process is as follows: Roast boronite ore at a high temperature of 700~800°C, leach boronite ore with concentrated sulfuric acid, leaching with sulfuric acid, concentrate, add monohydric alcohol and let it stand for filtration, and the filtrate is reduced and concentrated by positive trivalent iron powder or iron filings Finally, add monoalcohol and then filter, cool and crystallize and dry to obtain solid MgSO ₄ ·7H ₂ O, FeSO ₄ ·7H ₂ O and boric acid solution.

Example 1

Main chemical composition of boronite (%): B ₂ O ₃ : 7.22%, TFe: 30.0%, MgO: 24%

This is low-grade boronite, with low boron content and high iron content, so the separation of iron compounds has an important impact on the separation of other compounds. The reaction should control the amount of reducing agent to reduce ferric iron to divalent, In order to achieve the separation of solid phase products.

The preparation process is as follows: put boronite in a muffle furnace and heat at high temperature (800°C) for 2.5 hours, accurately weigh 5.00g of calcined boronite, add 15mL of distilled water, 5mL of 98% concentrated sulfuric acid, and place it in a constant temperature water bath at 80°C Heat and stir for 1h. After hot suction filtration, put the filtrate on the heating furnace to 20mL, add 20mL of absolute ethanol after cooling, put it into the ice-water mixed solution for 1 hour after stirring, suction filtration, put the filtrate on the heating furnace until boiling, and volatilize a large amount of Recover ethanol, then add 0.5g iron wire to reduce Fe ³⁺ , cool it with running water immediately, add 20mL of absolute ethanol, put it in the mixed solution of ice and water for 30min, filter with suction, put the filter cake in an oven at 55℃ for 1h, and then FeSO ₄ •7H ₂ O was obtained with a crystallization rate of 90.0%. After the filtrate evaporates and recovers ethanol, the main component is boric acid.

Example 2

Main chemical composition of boronite (%): TFe: 22.91; B ₂ O ₃ : 7.55; MgO: 30.91; SiO ₂ : 18.29; CaO: 0.72.

This is a low-grade boronite with low boron content and high magnesium content, so the separation of magnesium compounds has an important impact on the separation of other compounds.

The boronite is oxidized and roasted at 780°C. The boronite in the boronite is transformed into suianite, and the magnetite is transformed into hematite. The antigorite in the mineral will decompose and remove the structural water after roasting, and the crystal structure A phase change occurs, transforming into olivine minerals, and roasting causes an increase in the specific surface area to meet the needs of sulfuric acid leaching reactions.

Put boronite in a muffle furnace and heat at high temperature (780°C) for 2.5h, weigh 10.0g of calcined boronite, add 50mL of 50% sulfuric acid, heat and stir in 80°C constant temperature water bath for 1h. After hot suction filtration, place the filtrate on a heating furnace to 40mL, add 20mL of absolute ethanol after cooling, put it in a water bath at 10°C for 1 hour after stirring, and filter with suction to obtain MgSO ₄ •7H ₂ O. Put the filtrate on the heating furnace until boiling, volatilize the ethanol and recover it, then add 0.8g iron wire to reduce Fe ³⁺ , cool it with running water immediately, add 30mL of absolute ethanol, let it stand at room temperature for 30min, suction filter, and put the filter cake in In an oven at 55°C for 1 hour, FeSO ₄ •7H ₂ O can be obtained. The crystallization liquid is evaporated and ethanol is recovered, and boric acid is enriched in the crystallization liquid.

Example 3

The main chemical composition (%) of boronite: B ₂ O ₃ : 10.87%, TFe: 6.01%, MgO: 37.56%.

This is a low-grade boronite, with low boron content and high magnesium content, so the separation of magnesium compounds has an important impact on the separation of other compounds. The main ore composition is boronite phase, dolomite phase, limestone phase, Serpentine phase, magnetite phase.

Oxidize and roast the boronite at 780°C, the boronite in the boronite is transformed into suianite, and the magnetite is transformed into hematite. Weigh 10.0g of the roasted boronite into a three-necked flask and add 20% The amount of sulfuric acid is 85% of the theoretical amount, the reaction temperature is 90~100°C, and the reaction time is 100min. All the other operations are the same as example 2.

Claims (2)

1. A process for extracting and separating boron-iron-magnesium from boron ore, characterized in that, the process is composed of three technical operations: high-temperature roasting of boron ore sulfuric acid leaching process; using the addition of organic solvents to crystallize magnesium salts Process; iron ferric iron powder reduction in acid leaching solution and organic solvent crystallization process; the process flow is: roast boronite at a temperature of 700~800°C, then leaching boronite with concentrated sulfuric acid, and after solid-liquid separation, Add monohydric alcohol to the pickling solution and let it stand still, filter to obtain solid MgSO ₄ 7H ₂ O, after the filtrate is reduced and concentrated by positive ferric iron powder or iron filings, add monohydric alcohol, then filter, cool and crystallize and dry to obtain solid FeSO ₄ • 7H ₂ O, the crystallization liquid contains boric acid; during the roasting process of boronite, the magnetite is converted into hematite; the organic solvent is monohydric alcohol. 2. A kind of technique that extracts and separates boron-iron-magnesium from boron-iron ore according to claim 1, is characterized in that, described organic solvent is recycled.