594
H. Nakano et al.
This paper reports major topics about the plan, such as “Improvement of working environment around furnaces”, “Rationalization of the closed mines monitoring”, “Treatment of high concentration fluorine wastewater”, and “Improvements of
separation work of waste lead-acid battery”.
Process Description of Hosokura Smelter
The process flow for recycling spent lead-acid batteries in Hosokura smelter is shown
in Fig. 1.
At first, the spent lead-acid batteries are collected to the pre-treatment plant and
separated into three parts: electrolyte, grids and pastes, and plastic cases. The grids
and pastes are then charged into a blast furnace with coke, fluxes, and iron scraps
and reduced to bullion. Lead containing residues from copper smelters are also fed to
the furnace in order to recover gold and silver as well as lead. The bullion is refined
in kettles by copper drossing and Harris softening, and then molded into anodes.
The anodes are transferred to the tank house equipped with 180 cells and finally
electrorefined by Betts process.
Various by-products are produced from the anode slimes and the copper drosses.
The anode slimes are charged into a short rotary furnace and reduced into black
metal. The black metal is, then, transferred to a kettle and oxidized to burn-down
metal with vaporizing of Sb 2 O 3 . The burn-down metal is transferred to a cupel and
further oxidized to dore metal with top blown air. A Bi-rich phase is also recovered
in cupellation and processed to metallic bismuth. Dore metal is finally treated in the
anode furnace and molded into silver anodes. On the other hand, the copper-bearing
drosses are smelted to recover lead and copper matte in another short rotary furnace.
Both the silver anodes and the copper mattes are sent to a copper smelter equipped
with a precious metal plant.
Improvement of Working Environment Around Furnaces
Problems in the Working Environment Around Furnaces
Working environment around the blast furnace and the short rotary furnaces used
to be very dusty by lead fumes and dusts, and so the blood lead concentrations of
the workers were risen. For this reason, it was necessary to improve the working
environment around furnaces and to reduce the dust concentration in the air around
furnaces.
H. Nakano et al.
This paper reports major topics about the plan, such as “Improvement of working environment around furnaces”, “Rationalization of the closed mines monitoring”, “Treatment of high concentration fluorine wastewater”, and “Improvements of
separation work of waste lead-acid battery”.
Process Description of Hosokura Smelter
The process flow for recycling spent lead-acid batteries in Hosokura smelter is shown
in Fig. 1.
At first, the spent lead-acid batteries are collected to the pre-treatment plant and
separated into three parts: electrolyte, grids and pastes, and plastic cases. The grids
and pastes are then charged into a blast furnace with coke, fluxes, and iron scraps
and reduced to bullion. Lead containing residues from copper smelters are also fed to
the furnace in order to recover gold and silver as well as lead. The bullion is refined
in kettles by copper drossing and Harris softening, and then molded into anodes.
The anodes are transferred to the tank house equipped with 180 cells and finally
electrorefined by Betts process.
Various by-products are produced from the anode slimes and the copper drosses.
The anode slimes are charged into a short rotary furnace and reduced into black
metal. The black metal is, then, transferred to a kettle and oxidized to burn-down
metal with vaporizing of Sb 2 O 3 . The burn-down metal is transferred to a cupel and
further oxidized to dore metal with top blown air. A Bi-rich phase is also recovered
in cupellation and processed to metallic bismuth. Dore metal is finally treated in the
anode furnace and molded into silver anodes. On the other hand, the copper-bearing
drosses are smelted to recover lead and copper matte in another short rotary furnace.
Both the silver anodes and the copper mattes are sent to a copper smelter equipped
with a precious metal plant.
Improvement of Working Environment Around Furnaces
Problems in the Working Environment Around Furnaces
Working environment around the blast furnace and the short rotary furnaces used
to be very dusty by lead fumes and dusts, and so the blood lead concentrations of
the workers were risen. For this reason, it was necessary to improve the working
environment around furnaces and to reduce the dust concentration in the air around
furnaces.