Method and apparatus for measuring metal portion in dross

摘要

Method and apparatus for determination of portion of pure metal in dross from a dross source, whereby the metal portion in the dross is determined by measuring the dross density and calculating the metal portion in accordance with the formula m%=k−ρ+a, where m% is percentage pure metal, ρ is the dross density and k and a are empirical constants. In accordance with the invention, the apparatus comprises a closed container (1) for dross provided with temperature gauge (9), pressure gauge (8) and an outlet pipe (18) having a valve (12) for removal of gas from the dross container (1), a closed container (2) for gas provided with a valve (14) for supplying gas from a gas source (16) to the gas container (2), whereby the dross container (1) and the gas container (2) are in a flow connection via a pipe (20).

主权项

1. A method for determining portion of pure metal in dross from a dross source, whereby the metal portion is determined by measuring the dross density and calculating the metal portion in accordance with the formula m%=k·ρ+a, wherein m% is percentage pure metal, ρ is dross density, and k and a are empirical constants, whereby the density is determined by:
transferring dross having known mass from the dross source to a closed container having a known volume, closing the dross container and evacuating gas from the dross container, supplying a gas to the closed container, reading the amount of gas supplied to the closed container, wherein the dross having a temperature of up to 600 to 800° C. is transferred to a closed container system comprising the dross container and a gas container containing an inert gas, wherein the method further comprises the following steps: supplying a gas at a pressure above atmospheric pressure to the gas container; closing the gas container; measuring temperature and pressure inside the closed gas container; opening a gas line between the closed gas container and the closed dross container; allowing the pressure between the dross container and gas container to become equalized; and measuring the temperature and pressure of the dross container and the gas container before opening the dross container to the atmosphere; and then calculating the dross density and the portion of pure metal in the dross.