Propriétés du minerai et sélection de la technologie de flottation

Introduction to Ore Characteristics

The composition and properties of ore significantly influence mineral flotation efficiency. Key factors include:

• Composition minérale: Type, content, and distribution of valuable minerals and gangue.
• Ore genesis: Primary (e.g., sulfide/oxide minerals) vs. secondary mineralization.
• Impurities and isomorphic substitution: Presence of soluble salts or trace elements (e.g., iron in sphalerite affecting floatability).
• Oxydation de surface: Variations during mining, storage, or transportation.

Different deposits of the same mineral may exhibit distinct flotation behaviors due to formation conditions, structural variations, and impurity content. For example, the floatability of galena or sphalerite collected from different producing areas is very different, especially the different colors of sphalerite (related to the amount of impurities such as iron and cadmium) are more prominent. The floatability of apatite, calcite, or barite produced in the production area is also very different. The reason for this phenomenon is mainly related to the conditions for the production of minerals and the entry of impurities into the minerals in the same way. In addition, during the mining, transportation, and storage of ore, the floatability of the mineral may also change due to the oxidation of the mineral surface and the contamination of impurities.

Impact of Mineral Formation on Floatability

Les conditions de formation des minéraux utiles affectent la structure des minéraux et ont une forte influence sur la flottabilité des minéraux. Les minéraux sulfurés générés dans des conditions de pression et de température élevées, tels que ceux séparés du magma en fusion ou précipités à partir de fluides hydrothermaux, ont généralement une structure relativement compacte, sans pores intermédiaires, et la taille géométrique des cristaux minéraux est relativement importante.

La séquence de formation des minéraux peut avoir un impact important sur la flottation. When there are cracks in the minerals formed earlier, they are often filled with minerals formed later to become vein-like or net-like structures. In the process of crushing and grinding, new fracture surfaces often appear along the fine mesh veins of the ore, and the secondary minerals are more prone to slumping.

Pendant le processus de minéralisation, enrichissement secondaire sometimes occurs; that is, after some primary sulfide minerals interact with other metal salt solutions, they precipitate to form a rich ore zone at the contact between the oxide ore and the primary sulfide ore. Due to secondary enrichment, films with different compositions are often formed on the surface of primary sulfide minerals. A typical example is that the surface of pyrite is covered with chalcocite or a copper blue film; it is also common that the surface of chalcopyrite is covered with copper blue, and the surface of sphalerite is covered by a silverite film. Obviously, during crushing and grinding, it is very difficult to completely separate the covering film on the mineral surface from the mineral, resulting in the mineral having floatability similar to that of the covering film.

Il convient de souligner que les deux changements suivants ont un impact particulièrement important sur les propriétés de flottation des minéraux. silicification; l'autre est kaolinization, chloriteization, and sericitization. In the first case, the minerals are glued by silica; in the second case, many very different microcrystalline minerals are formed, which will produce a large amount of fine mud during the grinding process.

Selon les types de minéraux symbiotiques, le degré de difficulté de la séparation par flottation est également très différent, parce que dans la séparation par flottation, non seulement un ou plusieurs minéraux sont faciles à flotter dans le produit mousseux, mais aussi d'autres minéraux qui ne devraient pas flotter. Facilité de contrôle. Par exemple, il n'y a aucune difficulté à utiliser des collecteurs d'acides gras pour faire flotter la scheelite à partir du quartz, mais si la gangue est de la calcite, de la fluorite ou de la dolomite, la séparation par flottation est très compliquée ; les composés sulfurés sont utilisés à partir de minéraux non sulfurés Il est également relativement simple pour les collecteurs de faire remonter à la surface les minéraux sulfurés, mais il est beaucoup plus difficile de séparer les minéraux sulfurés concentrés ou les minéraux sulfurés partiellement oxydés les uns des autres.

Ore Blending Strategies for Stable Flotation Performance: From Mining to Processing

La nature du minerai est un facteur objectif difficile à modifier., so corresponding technological measures must be taken in the practice of flotation production to adapt to the nature of the ore and its changing law. In order to establish a relatively stable process operation system and obtain a relatively stable flotation index, the ore entering the concentrator should be relatively stable in nature to facilitate management. This often requires the cooperation of mining and beneficiation workers. Can be achieved. For example, before blasting, some mines first sample and analyze the ore in each pit and face each face, to roughly find out the grade and composition of the ore blasted from each face, and then, according to each face, Proper ore blending is performed in proportion to the amount of ore produced. Some mines are equipped with special ore blending sites to maintain the relatively stable nature of the ore beneficiation process; some concentrators also perform ore blending by feeding and unloading during the crushing process; In other dressing plants, the grinding products are mixed through a public épaississeur to mix the grinding products of the whole field, and remove excess water or fine mud, so that the feed concentration of the flotation operation is also relatively stable.

How Do You Select a Flotation Process?

Le choix du procédé de flottation dépend de la taille des particules et des caractéristiques des boues des minéraux utiles contenus dans le minerai.
There are five types of inlay granularity: coarse-grained inlay, fine-grained uniform inlay, uneven in thickness, complex uneven inlay, and aggregate inlay.

• For coarse-grained embedded ore, because the particle size of the embedded cloth is coarse, it is easy to separate useful minerals from the gangue. It is advisable to use the two-stage flotation principle process of regrinding the medium ore;
• Coarse grains and fine grains. In one stage, part of the coarse-grained qualified concentrate can be obtained, and the fine-grained contiguous body is reground and re-selected. It is advisable to use the two-stage flotation principle process or the three-stage flotation principle process of the tailings regrind;
• Evenly embedded ore, because the particle size of the embedded ore is extremely uneven, and the dissociation range is very wide, it is appropriate to use the three-stage flotation principle process;
• In aggregate ore, because the useful minerals are contained in a larger aggregate, during rough grinding it is easy to separate the aggregate from the gangue. It is advisable to use the two-stage flotation principle process of regrinding the two ends of the coarse concentrate (ie aggregate) or the two-stage flotation principle of regrinding the middle ore.

Lors de la sélection d'un procédé de flottation multi-métaux, outre l'influence des caractéristiques granulométriques du tissu incorporé sur le procédé, il convient également de tenir compte de l'influence de la flottabilité des différents minéraux et d'autres facteurs sur la sélection du procédé. 

• For three types of ores, such as high-grade raw ore, low gangue content, coarse-grained distribution, or simple ore properties, large difference in the floatability of useful minerals, easy separation, or containing a large amount of dense polymetallic sulfide ore, direct priority should be given to the principle flow of flotation;
• For the ore with medium grade of raw ore, or poor and coarse aggregates, or ore containing a small amount of polymetallic sulfide ore, it is advisable to use the principle flow of full mixed flotation;
• For the complex polymetallic ore with “equal floatability”, it is advisable to use part of the part-mixed flotation principle process.

Conclusion

Ore properties dictate flotation design. Process selection must align with mineralogy, texture, and liberation characteristics, supported by blending and staged grinding where needed. Continuous ore characterization ensures adaptive and efficient separation. Stable feed properties and process flexibility are critical for optimizing metallurgical performance.