headerdrawing1.jpg (96365 bytes)

Sulphuric Acid on the WebTM Technical Manual DKL Engineering, Inc.

Knowledge for the Sulphuric Acid Industry Line.jpg (1139 bytes)

Sulphuric Acid on the Web

Equipment Suppliers

Industry News
Acid Traders

Used Plants
Intellectual Propoerty
Acid Plant Database
Market Information

Technical Manual


Plant Safety
Metallurgial Processes
Sulphur Burning
Acid Regeneration
Lead Chamber
Gas Cleaning
Strong Acid
Acid Storage

Sulphur Systems
Liquid SO2
Boiler Feed Water
Steam Systems

Cooling Water
Effluent Treatment
Analytical Procedures
Materials of Construction
Vendor Data

DKL Engineering, Inc.

Handbook of Sulphuric Acid Manufacturing
Order Form

Sulphuric Acid Decolourization
Order Form
Table of Contents

Process Engineering Data Sheets - PEDS
Order Form
Table of Contents


Bibliography of Sulphuric Acid Technology
Order Form


Sulphuric Acid Plant Specifications

Google Search new2.gif (111 bytes)



Acid Plant Database  November 16, 2016

Owner Mitsubishi Materials Corporation

Mitsubishi-Logo.gif (2237 bytes)

Location 4049-1 Naoshima-cho
Japan 761-31
Background -


Plant Naoshima Smelter and Refinery
L-1 L-2 L-3
Coordinates* - 34° 28' 23" N, 133° 58' 37" E 34° 28' 21" N, 133° 58' 32" E
Type of Plant Metallurgical Metallurgical
Gas Source - Copper
Mitsubishi Continuous Smelting Process (to both plants)
Anode Furnace (to both plants)
Spent Acid Decomposer (to Plant No. 2)
Gas Cleaning - Venturi Scrubber - No. 1 Gas Cooler - 1st Stage WESP - No. 2 Gas Cooler - 2nd Stage WESP Venturi Scrubber - Gas Cooler - 1st Stage WESP - 2nd Stage WESP
Plant Capacity 220 MTPD 850 MTPD
1270 Nm3/min, 10% SO2
1000 MTPD
1670 Nm3/min, 10% SO2
Emissions - SO2: 3500 ppm SO2: 3300 ppm
Status 1988 Shutdown Operating Operating
Year Built - 1969 1974
Technology - Outotec (Lurgi) Outotec (Lurgi)
Contractor - - -
Remarks   -

- Originally double absorption but converted to single absorption with tail gas scrubbing in 1986 after failure of one of the absorption towers.
- Oleum produced in Plant

- Equipped with two stage drying towers.  Primary produced lower concentration acid when feed gas was low SO2 from the old reverberatory furnance which was shut down in 1991.  Presently, produces 50% acid which is sent to a neutralization gypsum plant.
- Acid coolers are PTFE Coils (1997)

- Tail gas scrubber is a basic aluminum sulfate-gypsum process
2013 - Venturi scrubbers replaced with humidifying and washing towers (Both L-2 and L-3)
2013 - 3AT blower changed from a fluid coupling to inverter control (VFD)
2013 - Drying tower replaced
2014 - Graphite.carbon shell and tube condensers for gas cooling replaced with packed gas cooling tower (Both L-2 and L-3)
2015 - Production tank changed from bricklined SS to SX steel
20?? - PTFE acid coolers replaced with plate and frame HX
General 1994 - April - Lead smelting and refining facility at Naoshima closed.  Mitsubishi Materials took over the Naoshima plant from Mitsubishi Cominco Smelting Co. in October 1991. The plant processed exclusively ore from the Pine Point Mine in Canada until April 1992, when that mine's supply was exhausted. This forced the Naoshima lead-processing facility to supplement its pyrometallurgical smelter with a tank-house refinery to handle more varieties of ores from other mines.
References Sakurai, F. and Yagishita, S., "Recent Improvements in the Acid Plant at Naoshima Smelter", Sulfide Smelting 2002, pp. 133-141.
Yamaguchi, H., Morigami, W. and Zen, H., "Intentional Modification of Acid Plants for Coping Successfully with Smelter Off-Gas at Naishima Smelter & Refinery (NSR), Copper 2016, Kobe, Japan.
News March 10, 2010 - Mitsubishi Materials Corp., Japan’s third-largest copper producer, may run its two domestic smelters at full capacity in the next fiscal year, in contrast to plans by two rivals to keep production cuts, an executive said.  “At the moment, that’s the plan,” Kenichi Watase, general manager in the Tokyo-based company’s sales department, said in an interview today. Watase declined to elaborate as the company expects to issue its output targets for April to September early next month. The producer planned to make 300,000 metric tons in the year ending March 31.  Prices of copper, used in pipes and cables, more than doubled in the past year as the global economy recovered from its worst postwar recession. BHP Billiton Ltd. and Freeport- McMoRan Copper & Gold Inc. won a 38 percent cut in 2010 processing fees from smelters as raw material supplies tightened after China expanded capacity.  Pan Pacific Copper Co. and Sumitomo Metal Mining Co. have said they may keep production cuts in the year from April 1 because of the lower fees.  Mitsubishi Materials operates the Onahama smelter, to the north of Tokyo, with a capacity of 258,000 tons, and the Naoshima smelter, in western Japan, with 225,000 tons. The company has a 50 percent stake in the Onahama smelter.   The company “is flexible on adjusting production based on the market situation in coming months” given the reduced fees and uncertain demand outlook at home and abroad, Watase said. “We don’t know whether a recovery in demand from the auto sector will continue after subsidies end later this year.”
“After domestic demand plunged last year to the lowest level since 1975, we’ve seen a recovery in some sectors, including cars and semiconductors, not from overall industries,” in recent months, Watase said.  The Japanese government has extended the subsidy program, which was set to expire at the end of March, for six months through September. Electric, hybrid, natural-gas, and some diesel vehicles qualify for an exemption from the country’s weight and purchase taxes.  Exports to China “will depend on Chinese government policies and the price difference between the Shanghai market and the London Metal Exchange,” Watase said. “In my personal view, China’s demand growth would remain steady this year.”
Asked if Mitsubishi Materials saw any change in the market for sulfuric acid, a byproduct for copper smelting, Watase said demand has recovered from fertilizer makers and mining companies.  “We’ve seen good demand for the fertilizer sector in North America as the planting season for grain crops starts soon,” Watase said. Sulfuric acid supplies have been tight since early January as demand jumped after a recession slashed stockpiles held by fertilizer makers and mining, he said.  The value of sulfuric acid, used to dissolve metal ore and produce fertilizer, has gone from worthless to “crazy” this year, increasing costs for mining companies, according to London-based researcher CRU Group said.  Demand from fertilizer makers, normally about half of world sulfuric acid consumption, has risen as higher prices for their products prompted companies to rebuild stocks, Joanne Peacock, an analyst at CRU, said March 8.

MTPD - Metric Tonne per Day           STPD - Short Ton per Day
MTPA - Metric Tonne per Annum      STPA - Short Ton per Annum
SA - Single Absorption
DA - Double Absorption

* Coordinates can be used to locate plant on Google Earth