Operação do processo de beneficiamento químico

Overview of Chemical Beneficiation

Beneficiação química is a mineral processing method based on differences in the chemical properties of minerals and their components. It uses chemical reactions, dissolution, precipitation, ion exchange, solvent extraction, and other chemical techniques to alter the composition or chemical form of minerals, thereby separating and enriching valuable components.

For example, malachite-bearing copper ore can be leached with dilute sulfuric acid. During leaching, malachite is converted into a copper sulfate solution. Copper metal can then be recovered from the solution by cementation, in which iron filings replace copper ions to produce metallic copper, commonly known as sponge copper.

Chemical beneficiation is particularly effective for processing low-grade, fine-grained, complex, and refractory mineral resources that are difficult to treat using conventional physical beneficiation methods. It can improve resource utilization, recover valuable components from previously uneconomic materials, and contribute to the treatment and utilization of waste streams such as wastewater and waste residues.

A typical chemical beneficiation process consists of six major operations:

• Preparatory work
• Assar
• Leaching
• Separação sólido-líquido
• Purification
• Recovery of chemical concentrates

The specific process configuration depends on the mineral composition, the properties of the valuable components, and the required product quality.

 

Processo de beneficiamento químico

A beneficiação química tem diferentes operações de acordo com diferentes processos tecnológicos. Um processo típico de beneficiação química inclui geralmente as seis operações primárias seguintes.

 

 

1. Preparatory Work

Esta operação é a mesma que o método de beneficiação física, incluindo trituração e peneiração de materiais, moagem e classificação, mistura de ingredientes e outros processos de processamento mecânico. The purpose is to grind the material to a specific particle size, prepare suitable fineness and concentration for the next operation, and sometimes use physical beneficiation to remove some harmful impurities or enrich the target minerals in advance so that the mineral raw materials and chemical reagents are mixed well. If the fire method is used, sometimes the material must be dried or sintered to create favorable conditions for the next operation.

2. Roasting Operation

The purpose of roasting is to change the chemical composition of the ore or remove harmful impurities so that we can transform the target mineral (component) into a form that is easy to leach or beneficial to physical beneficiation and prepare conditions for the next operation. The roasted products include calcined sand, dry dust, wet dust collection liquid, and mud, from which corresponding methods can recover functional components according to their composition and properties.

3. Leaching Operation

Esta operação consiste em dissolver seletivamente os componentes funcionais ou os componentes de impureza no solvente de lixiviação, de acordo com as propriedades das matérias-primas e os requisitos do processo, de modo a que os componentes valiosos sejam separados dos componentes de impureza, ou os componentes funcionais sejam separados, que é o passo seguinte. Criar condições para a recuperação de componentes úteis da solução de lixiviação ou do resíduo de lixiviação.

4. Solid-liquid Separation Operation

This is the same as the dehydration operation of physical beneficiation products, but the solid-liquid separation of chemical beneficiation leached pulp is more complicated. Generally, sedimentation, filtration, and classification are used to process leached ore pulp to obtain a clarified solution or contain a small number of fine mineral particles.

5. Purification Work

To obtain high-grade chemical concentrates, the leaching solution is often purified and separated by chemical precipitation, ion exchange, or solvent extraction to remove impurities and obtain a purified solution with a high content of valuable components.

6. Production of Chemical Concentrates

Chemical concentrates are obtained by extracting valuable metals (components) from the leaching solution. Generally, chemical precipitation, metal replacement, electrowinning, carbon adsorption, ion exchange, or solvent extraction can be used; in some cases, physical beneficiation can also be used. The principal process of typical chemical beneficiation is as follows.

 

 

Tem utilizado com sucesso a beneficiação química para processar muitos minerais metálicos e matérias-primas minerais não metálicas, tais como ferro, manganês, chumbo, cobre, zinco, tungsténioalumínio, estanho, ouro, pratatântalo, nióbio, cobalto, níquelO processo de extração de minério de ferro, urânio, tório, terras raras, alumínio, fósforo, grafite, diamante, caulim e outras matérias-primas minerais sólidas. Também pode extrair componentes valiosos da água de minas, águas residuais e água do mar.

The processing object of characteristic chemical beneficiation is the same as that of physical beneficiation. Still, the adaptability of the chemical beneficiation method is stronger than that of the physical beneficiation method, and its separation principle and product form are different from physical beneficiation. The separation principle of chemical beneficiation is similar to the traditional metallurgical process. Chemical beneficiation and the metallurgical process both use the basic principles of inorganic chemistry, organic chemistry, physical chemistry, and chemical processes to solve their respective process problems. Mineral dressing is widely used in developing various refractory ferrous metals, non-ferrous metals, precious metals, and non-metallic mineral resources.

A aplicação da beneficiação química é um método eficaz para lidar com matérias-primas minerais pobres, finas, diversas e outras matérias-primas minerais refractárias e reciclar recursos minerais não utilizados. A sua eficiência de separação é superior à da beneficiação física. No entanto, o processo de beneficiação química consome muitos produtos químicos e os requisitos para os materiais de equipamento e a separação sólido-líquido são mais elevados do que os da beneficiação física. Por conseguinte, em condições normais, deve utilizar os métodos de beneficiação física existentes para processar, tanto quanto possível, as matérias-primas minerais.

Quando considerar a utilização de um processo de beneficiação química?

• Não pode ser processado apenas por beneficiação física.
• Quando o método de beneficiação física não consegue obter indicadores técnicos e económicos razoáveis

 

When Should Chemical Beneficiation Be Considered?

Chemical beneficiation should generally be considered under the following conditions:
1. Physical Beneficiation Alone Is Ineffective
When valuable minerals are extremely fine-grained, closely associated with gangue, disseminated, or chemically similar to the surrounding minerals, conventional physical beneficiation may not achieve satisfactory separation.
2. Physical Beneficiation Cannot Achieve Reasonable Technical and Economic Indicators
If physical beneficiation cannot provide acceptable recovery, concentrate grade, or economic performance, chemical treatment may provide an alternative or supplementary solution.
3. Valuable Components Occur in Complex or Refractory Forms
Chemical beneficiation is particularly suitable when valuable components occur in forms that are difficult to recover through conventional gravity, magnetic, flotation, or other physical methods.

 

 

Precautions When Using The Chemical Beneficiation Process

• Utilizar, tanto quanto possível, processos em circuito fechado. Regenerar totalmente o medicamento e reciclar a água para reduzir o consumo de medicamentos e a poluição ambiental.
• O processo conjunto de beneficiação física e de beneficiação química deve ser adotado tanto quanto possível. São utilizados vários métodos de beneficiação para processar as matérias-primas minerais, a fim de obter a utilização mais económica e abrangente dos recursos minerais.

 

Conclusão

Chemical beneficiation is an important mineral processing technology for treating low-grade, fine-grained, complex, and refractory mineral resources. By utilizing differences in chemical properties and employing operations such as roasting, leaching, solid-liquid separation, purification, and valuable-component recovery, it can achieve separations that are difficult or impossible to accomplish through physical beneficiation alone.

However, chemical beneficiation generally requires greater consumption of chemical reagents and places higher demands on equipment, materials, solid-liquid separation, and environmental management. Therefore, it should not automatically replace physical beneficiation.

In practice, physical beneficiation should be used whenever it can provide satisfactory technical and economic results, while chemical beneficiation should be introduced where necessary and, whenever possible, integrated with physical beneficiation. The optimal process should maximize valuable-component recovery, minimize reagent and water consumption, promote closed-loop operation, reduce environmental impact, and achieve comprehensive and economical utilization of mineral resources.