Fonctionnement du processus d'enrichissement chimique

Overview of Chemical Beneficiation

Valorisation chimique 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
• Torréfaction
• Leaching
• Séparation solide-liquide
• 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.

 

Processus d'amélioration chimique

L'enrichissement chimique comporte différentes opérations en fonction des différents processus technologiques. Un processus d'enrichissement chimique typique comprend généralement les six opérations primaires suivantes.

 

 

1. Preparatory Work

Cette opération est identique à la méthode d'enrichissement physique, y compris le concassage et le criblage de matériaux, le broyage et le calibrage, le mélange d'ingrédients et d'autres processus de traitement mécanique. 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

Cette opération consiste à dissoudre sélectivement les composants fonctionnels ou les composants impurs dans le solvant de lixiviation en fonction des propriétés des matières premières et des exigences du procédé, de manière à séparer les composants utiles des composants impurs, ou à séparer les composants fonctionnels, ce qui constitue l'étape suivante. Créer les conditions permettant de récupérer les composants utiles de la solution de lixiviation ou du résidu de lixiviation.

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.

 

 

Elle a utilisé avec succès l'enrichissement chimique pour traiter de nombreux minéraux métalliques et matières premières minérales non métalliques, telles que fer, manganèse, plomb, cuivre, le zinc, tungstènel'aluminium, l'étain, l'or, argentle tantale, le niobium, le cobalt, nickelIl est possible d'extraire de l'eau des mines, de l'uranium, du thorium, des terres rares, de l'aluminium, du phosphore, du graphite, du diamant, du kaolin et d'autres matières premières minérales solides. Il peut également extraire des composants précieux de l'eau des mines, des eaux usées et de l'eau de mer.

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.

L'enrichissement chimique est une méthode efficace pour traiter les matières premières minérales pauvres, fines, diverses et autres matières réfractaires et pour recycler les ressources minérales inutilisées. Son efficacité de séparation est supérieure à celle de l'enrichissement physique. Cependant, le processus d'enrichissement chimique consomme beaucoup de produits chimiques et les exigences en matière d'équipement et de séparation solide-liquide sont plus élevées que celles de l'enrichissement physique. Par conséquent, dans des conditions normales, il convient d'utiliser les méthodes d'enrichissement physique existantes pour traiter les matières premières minérales autant que possible.

Quand faut-il envisager l'utilisation d'un procédé d'enrichissement chimique ?

• Il ne peut pas être traité uniquement par enrichissement physique.
• Lorsque la méthode d'enrichissement physique ne permet pas d'obtenir des indicateurs techniques et économiques raisonnables

 

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

• Utiliser autant que possible des processus en boucle fermée. Régénérer entièrement le médicament et recycler l'eau afin de réduire la consommation de médicaments et la pollution de l'environnement.
• Le processus conjoint d'enrichissement physique et d'enrichissement chimique devrait être adopté autant que possible. Diverses méthodes d'enrichissement sont utilisées pour traiter les matières premières minérales afin d'utiliser les ressources minérales de la manière la plus économique et la plus complète possible.

 

Conclusion

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.