Concept, classification and market supply and demand status of high-purity quartz sand for photovoltaic single crystal crucible
As one of the important raw materials of photovoltaic crucible, quartz sand plays an important role in the quality of photovoltaic crucible. Then, what quality quartz sand is used for the crucible? How to distinguish? How about market demand and supply? Now let's have a look!
1. The main sources of quartz sand used in photovoltaic crucible are: domestic ores, American ores, and imported ores other than non American ores (mainly from India, and quartz shares are nearly all inclusive monopoly)< br/>
2. The quartz sand used for photovoltaic crucible is divided into inner, middle and outer layers. The inner layer mainly uses American mineral sand, the middle layer uses Indian mineral sand, and the outer layer uses domestic mineral sand. The proportion of sand used for the inner, middle and outer layers is 4:3:3 respectively< br/>& nbsp;
3. As the Indian mineral sand is mainly monopolized by quartz shares, the quartz shares import Indian ores and purify them in China. The purified quartz sands are not imported high-purity quartz sands, but become domestic quartz sands and domestic high-purity quartz sands< span style="text-indent: 2em;">& nbsp;
After the Indian mineral sand is purified in China, it is mainly used in the middle layer of the crucible. In addition, the high-purity quartz sand, which accounts for about 5% of the total output (because the Indian mineral ore is getting deeper and deeper, the purity is also rising, and it is expected to increase to 10% next year), can also be used as the inner layer crucible (mainly used in small size, or inner layer doping). At present, India has a large amount of ore mining and a high enthusiasm to expand production, so the supply will not become a bottleneck< br/>
4. Can Indian ore be used as quartz sand in the inner layer of large size crucible< span style="text-indent: 2em;">& nbsp;
As the mining depth of Indian ore continues to increase, its purity begins to increase significantly. Although the purity index of high-purity quartz sand after purification of Indian ore is higher than that of American mineral sand, another key index will be a large number of bubbles during the use of crucible, and the large number of bubbles will lead to the local collapse of large size crucible under high temperature, This will lead to quality and safety production accidents.
5. After purification, domestic quartz ore is mainly used in the outer layer of the crucible. Domestic ore mining and production expansion are fast, and supply is unlikely to become a bottleneck.
6. American ore is the only quartz vein ore associated with granite found in the world at present. At present, this ore is unique to Unimin in the United States and TQC in Norway (mined by two companies). In addition to its relatively high purity, this ore is not easy to generate bubbles when it is used as the inner layer of sand, which is the actual optimal solution to use American ore as the inner layer of quartz crucible at this stage.
7. After screening and purification, quartz ore becomes high-purity quartz sand for photovoltaic crucible. At present, domestic purification technology and process have reached the most advanced level abroad, and China can also undertake the purification and OEM business of quartz sand from foreign large factories.
Therefore, the ore source is the main difference between the outer, middle and inner layers of sand, not determined by the purification production process. The following concepts must be distinguished: quartz sand is not equivalent to domestic high-purity quartz sand and imported high-purity quartz sand; Domestic high-purity quartz sand is not equivalent to imported high-purity quartz sand; Imported high-purity quartz sand refers to the special high-purity quartz sand for the inner layer after being purified with American ores.