The existing pyrometallurgical process to prepare metal niobium is complex, expensive, energy intensive and probably polluting.

现有的金属铌和铌基合金制备工艺复杂、成本高、能耗大、污染环境。

youdao

Tannery belongs to typical industrial branches which during the technological process produce considerable quantities of liquid and solid wastes contributing to polluting the environment.

制革属于典型的工业分支，制革工业中会产生大量的污染环境的废液和废固。

youdao

This process can make use of tailings as resource without polluting the environment, realizing the aim of non-tailing mine.

该工艺实现尾矿资源化的同时不会对环境造成污染，可以达到无尾矿矿山的目标。

youdao

In part, it's still the hangover from last summer's storms, but it's also caused by the process of changing over to gasoline that is less polluting in the warm weather, and that procedure is more disruptive this year because distributors are switching from the old chemical called NTBE, which has been found to pollute ground water, to ethanol.

NPR: Marketplace Report: Feeling the Pain at the Pump

That said, if the process really can be made to work, CO2 would go from being a polluting waste product to a valuable raw material, and it might even become worthwhile building systems to capture it and pipelines to ship it around.

ECONOMIST: Biofuels from algae: Craig's twist | The