黄渣

Speiss \Speiss\, n. [Cf. G. speise food, mixed metal for bells,
etc.]
1. (Metal.) A regulus consisting essentially of nickel,
obtained as a residue in fusing cobalt and nickel ores
with silica and sodium carbonate to make smalt.

2. (Metal.) Impure metallic arsenides, principally of iron,
produced in copper and lead smelting.
[Webster 1913 Suppl.]