Zambia's parliament will later on Wednesday debate the amended mines bill which proposes to reduce copper royalties to a variable tax of between 4 to 6 percent, depending on the price of the metal.
The Mines and Minerals Development (Amendment) Bill also proposes to reduce mineral royalties for other base metals to 5 percent for both underground and open cast operations.
The royalty would be 4 percent when the price of copper was below $4,500 a tonne, 5 percent when it was between $4,500 and $6,000 and 6 percent when above $6,000.
The new law also proposes to reduce the rate of mineral royalty for energy and industrial minerals to five percent for both underground and open cast mining operations.
Mineral royalty for gemstones and precious metals would be set at six percent for both underground and open cast mining operations.
Mining lobbies had asked for a price-based royalty structure to ease the tax burden during a period of depressed prices.
Zambia in June last year cut mineral royalties for underground mines to 6 percent from 9 percent and those of open cast mines to 9 percent from 20 percent following an outcry by mining firms.