Hibi Smelting Plant (currently Hibi Smelter) and Takehara Refinery Plant (currently Takehara Refinery) are acquired from Showa Mining Co., Ltd. and Hibi Smelter is created.
日比製煉所から竹原電煉工場を分離し、竹原製煉所を設置
Takehara Refinery Plant is separated from Hibi Smelter, and Takehara Refinery is created.
神岡鉱業(株)(当社前身)を設立。三井金属鉱業(株)と改称
三井鉱山(株)の金属部門をもって、神岡鉱業(株)(当社前身)を設立
東京証券取引所、第一部上場
Mitsui Mining Co., Ltd. spins off its metals division to establish Kamioka Mining and Smelting Co., Ltd. (The predecessor company of Mitsui Mining & Smelting Co., Ltd.).
Kamioka Mining and Smelting Co., Ltd. is listed on the First Section of the Tokyo Stock Exchange.
東京研究所(現基礎評価 / 機能材料研究所)を設置
Tokyo Laboratory (currently Materials Analysis & Exploration Center/R&D Center) is created.
神岡鉱業(株)から三井金属鉱業(株)へと商号を変更
Kamioka Mining and Smelting Co., Ltd. is renamed Mitsui Mining & Smelting Co., Ltd.
自動車機器事業開始。ダイカスト事業部設置
王子金属工業(株)および昭和ダイカスト(株)の両社を吸収合併、伸銅事業部・ダイカスト事業部を設置
Ohji Metals Co., Ltd. and Showa Die-cast Co., Ltd. are merged into Mitsui Mining & Smelting Co., Ltd, and Rolled Copper & Zinc Division and Die-casting Division are created.
串木野鉱業所を分離し、三井串木野鉱山(株)を設立
サンタ・ルイサ鉱業(株)の全株式を取得
Kushikino Mining is separated and Mitsui Kushikino Mining Co., Ltd. is established.
The purchase of all shares of Compania Minera Santa Luisa S.A. is completed.
八戸製錬(株)を設立
Hachinohe Smelting Co., Ltd. is established.
ワンサラ鉱山(ペルー)本格操業開始
日比共同製錬(株)を設立
Huanzala Mine (Peru) began its full-scale operations.
Mitsui Metal Foil Co., Ltd. and Sankin Rare Earth Co., Ltd. are merged into Mitsui Mining & Smelting Co., Ltd. Ageo Metal Foil Plant (currently Ageo Copper Foil Plant) and Miike Rare Metal Plant are created.
Taiwan Copper Foil Co., Ltd. is established in Taiwan.
全社事業部制移行
Mitsui Mining & Smelting Co., Ltd. becomes a profit center organization.
奥会津地熱(株)を設立
Okuaizu Geothermal Co., Ltd. is established.
神岡鉱業所と彦島製煉所を分離し、神岡鉱業(株)、彦島製錬(株)を設立
三池製錬(株)を設立
Kamioka Mining and Hikoshima Refinery are separated and reestablished as Kamioka Mining & Smelting Co., Ltd. and Hikoshima Smelting Co., Ltd.