Recent Operational Improvements
of Hematite Plant at Akita Zinc Co., Ltd.
Dai Matsuura, Yasuo Usami and Kenji Ichiya
Abstract AKITA ZINC Co., Ltd. (Iijima Zinc Refinery), jointly owned by DOWA
METALS & MINING Co., Ltd. (DMM) and another non-ferrous metal company,
has used the company’s own hematite process for iron control since the beginning of
operations in 1971. The amount of zinc leach residue for the hematite plant has been
increasing recent years due to the increase of iron content and decrease of zinc grade
in concentrate .In addition, some quality issues of by-product have been occurred
recently. The following solutions were carried out to stabilize hematite operation.
1. Zinc leach residue treatment increase
• Renewal of SO 2 leaching autoclave
• Improvement of cake-washing method
2. By-product quality improvement
• Modification of filter for de-arsenic process.
Keywords Hematite plant · Autoclave renewal · Cake-washing method
improvement · Filter modification
Introduction
DMM carries out mining and smelting activities for precious metals, PGMs, rare
metals, and base metals such as copper, lead, and zinc. It owns KOSAKA SMELTING
& REFINING Co., Ltd., producing copper and lead, and the AKITA ZINC Co.,
Ltd. (AZC) in Akita Prefecture. DOWA is a unique smelting company which has
established a metallurgical complex for copper, lead, and zinc, combining with a
recycling business.
AZC was established in 1971 with design capacity of 72,000 t/y zinc; it is jointly
owned by DMM and another non-ferrous metal company. AZC has increased its
D. Matsuura (B) · Y. Usami · K. Ichiya
Akita Zinc Co., Ltd., 217-9 Shimo-Kawabata Furumichi Iijima, Akita 011-8555, Japan
e-mail: matsuurd@dowa.co.jp
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_76
865
of Hematite Plant at Akita Zinc Co., Ltd.
Dai Matsuura, Yasuo Usami and Kenji Ichiya
Abstract AKITA ZINC Co., Ltd. (Iijima Zinc Refinery), jointly owned by DOWA
METALS & MINING Co., Ltd. (DMM) and another non-ferrous metal company,
has used the company’s own hematite process for iron control since the beginning of
operations in 1971. The amount of zinc leach residue for the hematite plant has been
increasing recent years due to the increase of iron content and decrease of zinc grade
in concentrate .In addition, some quality issues of by-product have been occurred
recently. The following solutions were carried out to stabilize hematite operation.
1. Zinc leach residue treatment increase
• Renewal of SO 2 leaching autoclave
• Improvement of cake-washing method
2. By-product quality improvement
• Modification of filter for de-arsenic process.
Keywords Hematite plant · Autoclave renewal · Cake-washing method
improvement · Filter modification
Introduction
DMM carries out mining and smelting activities for precious metals, PGMs, rare
metals, and base metals such as copper, lead, and zinc. It owns KOSAKA SMELTING
& REFINING Co., Ltd., producing copper and lead, and the AKITA ZINC Co.,
Ltd. (AZC) in Akita Prefecture. DOWA is a unique smelting company which has
established a metallurgical complex for copper, lead, and zinc, combining with a
recycling business.
AZC was established in 1971 with design capacity of 72,000 t/y zinc; it is jointly
owned by DMM and another non-ferrous metal company. AZC has increased its
D. Matsuura (B) · Y. Usami · K. Ichiya
Akita Zinc Co., Ltd., 217-9 Shimo-Kawabata Furumichi Iijima, Akita 011-8555, Japan
e-mail: matsuurd@dowa.co.jp
© The Minerals, Metals & Materials Society 2020
A. Siegmund et al. (eds.), PbZn 2020: 9th International Symposium
on Lead and Zinc Processing, The Minerals, Metals & Materials Series,
https://doi.org/10.1007/978-3-030-37070-1_76
865