lithopone grade

例句：

1. 1. The mineis producing high-quality lithopone, which is in demand in the market.
   该矿正在生产高质量的锂石，在市场上很受欢迎。
2. 2. The company has developed a newprocess to improve the quality of lithopone.
   该公司开发了一种新的工艺来提高锂石的质量。
3. 3. The lithium industry isfacing challenges due to the decline in lithopone grades.
   由于锂石品位的下降，锂行业正面临挑战。