HISTORY | Acids Co., Ltd.

History of Sulfuric Acid Business

Dowa Holdings (Formerly Dowa Mining)

1600	Sumitomo Metal Mining Dowa Holdings^**Formerly Dowa Mining 1691Sumitomo Metal Mining Sumitomo Family received permission from the Edo Shogunate to operate Besshi copper mine and began mining
1800	1884Dowa Holdings Fujita Group acquired the Kosaka Mine from the Meiji Government and established the mining business 1893Sumitomo Metal Mining Problem of smoke pollution in Niihama thought to be due to exhaust gas from copper smelting at Besshi Mine 1897Sumitomo Metal Mining As a measure against smoke pollution, commenced relocation of smelter to Shisakajima island (completed 1904)
1900	1905Sumitomo Metal Mining Complaints of smoke pollution on shore opposite Shisakajima 1905Dowa Holdings Smoke pollution from the Kosaka Mine spread to 10 municipalities in surrounding area. 1916Dowa Holdings Acquired Yanahara Mine (Okayama), commenced mining of iron sulfide ore. With development of various chemical industries, demand for sulfuric acid as a raw material increased Photo: Yanahara Mine 1929Sumitomo Metal Mining Introduced Petersen-process sulfuric acid production apparatus at Shisakajima Island smelter Production of sulfuric acid from sulfur dioxide in exhaust gas greatly reduced emission of sulfurous gas 1939Sumitomo Metal Mining Introduction of sulfur dioxide neutralization technology using ammonia at Shisakajima smelter completely eliminates sulfurous acid gas from its emissions Signed agreement at 11th Smoke Damage Council meeting. 47 years of smoke problem completely resolved 1952Dowa Holdings Introduced Dulco fluidized bed calcination furnace at Kosaka Mine. Started production of sulfuric acid from sulfur dioxide in exhaust gas 1953Dowa Holdings Started production of sulfuric acid using iron sulfide from Yanahara Mine With urgent need to increase production of chemical fertilizer to resolve food shortages after the war, demand for sulfuric acid increased 1962Dowa Holdings Kowa Seiko built Monsanto contact sulfuric acid plant in Kyushu 1969Dowa Holdings Sumitomo Chemical contact sulfuric acid plant built in Okayama, creating Japan’s largest sulfuric acid production facility, with a capacity of 1,100 tons/day 1971Sumitomo Metal Mining Toyo Smelter commissioning ceremony 1972Dowa Holdings Start of operations at Akita Zinc 1974Dowa Holdings Greatly expanded sulfuric acid production facilities in Okayama, creating maximum production capacity of 70,000 tons/month 1977Sumitomo Metal Mining Commenced modification of Toyo Smelter’s sulfuric acid production process (single contact type ⇒ double contact type) 1992Dowa Holdings End of iron sulfide mining with closure of Yanahara Mine 1994Sumitomo Metal Mining Sulfuric acid export facility completed in Niihama 1994Dowa Holdings Constructed sulfur roasting plant in Okayama, changing raw material from ore to sulfur (Raw material used in Kowa Seiko also changed from ore to sulfur in 1995)
2000	2001Dowa Holdings Kowa Seiko ceases production of sulfuric acid In the early 2000s, due to aging of Dowa Mining’s sulfuric acid production facilities and discontinuation of production at its Okayama plant resulting from rising costs, Sumitomo Metal Mining faced challenges in adjusting sulfuric acid supply in response to increased production of electrolytic copper. In order to resolve these issues, in February 2003, the two companies formed a business alliance and the joint venture company Acids Co., Ltd was established 2003Dowa Holdings Okayama factory ceases sulfuric acid production