Where Are Sulfuric Acid Plants in China? A Province-by-Province Sourcing Map

China’s sulfuric acid capacity divides into three technical routes with different geographic signatures: metallurgical off-gas acid attached to copper, nickel, lead, and zinc smelters; elemental sulfur-burning acid tied to phosphate fertilizer, caprolactam, and titanium dioxide parks; and pyrite-roasting acid concentrated in legacy inland sulfur-iron belts. The province-by-province sourcing map is therefore not a simple list of plant names but a matrix of production route, impurity origin, and transport mode. Industrial sulfuric acid commonly trades under GB/T 534-2014 as 98.0% or 92.5% H₂SO₄. The standard sets clauses for sulfuric acid content, residue on ignition, iron, arsenic, and transparency, but it does not cover every trace-element limit required by catalyst, electronic-grade, or battery-precursor buyers. Sourcing managers evaluate location because delivered cost and lot-to-lot quality variance are as much a function of the production route and logistics corridor as of the producing plant itself.

Which provinces form the smelter-acid backbone from Gansu to Fujian?

Smelter-acid capacity follows nonferrous smelting complexes rather than sulfur import terminals. In Gansu, the Jinchang nickel-copper complex generates acid from flash smelting and converting off-gas; the acid is a merchant supply item for the northwest but may require selenium and nickel trace control for specialty applications. In Anhui, Tongling’s copper smelting base feeds acid plants that treat converter gas through wet electrostatic precipitators before contact conversion; the commercial constraint is often arsenic in the feed gas, which is handled by scrubbing and bleed treatment rather than by product blending alone. Jiangxi’s Guixi copper complex is one of the largest metallurgical acid sources in the Yangtze basin and supplies baseload tonnage to phosphate and hydrometallurgical users, with barge and rail access determining how much acid can leave the province during peak fertilizer months.

Hubei contains both copper smelter acid near Daye and sulfur-burning units linked to phosphate complexes, creating a dual-route supply pool along the Yangtze. Yunnan’s copper and zinc smelters in the Kunming and Qujing areas supply regional phosphate demand and zinc hydrometallurgy; the logistics barrier is high-altitude rail capacity into Sichuan and Guangxi. Guangxi’s coastal smelter capacity at Fangchenggang can move acid by coaster or into Guangdong, while Fujian’s copper smelting source serves the southeast titanium dioxide and metal-finishing markets. In each case, the province name matters less than the smelter’s off-gas quality and the availability of dedicated acid storage at the receiving terminal.

This geographical spread means that a buyer in Guangdong may receive acid from Guangxi by coaster, from Jiangxi by rail, or from Shandong by coastal bulk tanker. The delivered product can be metallurgical or sulfur-burned acid with different limits for arsenic, selenium, mercury, and iron. Procurement specifications therefore need to state the production route acceptance limits, not only the concentration grade.

Smelter Acid Purity, Converter Cycle Variability, and Merchant Parcel Blending

Metallurgical acid quality is not constant across a smelter campaign. Converter aisle maintenance, feed concentrate changes, and dust carryover can shift iron, arsenic, and selenium levels in the acid plant feed. A plant that normally produces acid with iron below 30 mg/kg may deliver parcels above 100 mg/kg during upset conditions unless storage blending is used. This is why merchant smelter acid is often sold with lot-specific certificates rather than a fixed generic specification. Copper smelter acid from Anhui, Jiangxi, and Guangxi typically requires arsenic removal or dilution to meet tighter downstream limits. Lead-zinc smelter acid from Hunan, Liaoning, and Shaanxi may require mercury removal when the concentrate contains elevated mercury; the Boliden-Norzink process and equivalent sulfide precipitation systems can reduce mercury below 0.1 mg/kg when operated within their design range.

For applications where chloride, nitrate, and reducible substances are critical, GB/T 534-2014 is insufficient as the sole specification. Reagent-grade sulfuric acid under GB/T 625-2007 is a separate product category and is not a practical bulk solution for large-volume consumers. Large industrial users often impose additional internal limits on total arsenic below 0.0001%, total mercury below 0.0001%, and chloride below 0.0005%, depending on the process. These limits narrow the sourcing map toward sulfur-burned acid or specifically purified smelter acid, independent of province.

If Ammonium Phosphate Demand Tightens, Sichuan and Guizhou Sulfur-Burning Acid Shifts Into the Merchant Market

Sulfur-burning acid units in Sichuan and Guizhou are frequently captive to ammonium phosphate complexes. Acid is consumed in wet-process phosphoric acid reactors, and the amount available for external sale depends on monoammonium phosphate and diammonium phosphate operating rates. When phosphate demand is high, merchant availability from these provinces contracts and delivered acid in western and southern China tightens. When phosphate demand weakens, captive acid is sold into the merchant market, but rail tank car availability and dangerous goods marshalling rules determine whether Guizhou acid can reach Guangdong or Guangxi. Sulfur feedstock for these inland plants typically arrives through Yangtze ports, so low-water periods on the upper Yangtze can raise delivered sulfur cost and reduce acid plant operating rates even without a change in acid demand.

In a typical sulfur-burning contact acid plant, liquid sulfur is combusted at 135–145°C in dried air with a dew point below −40°C, producing a gas stream with 10–12 vol% SO₂. The double-contact double-absorption circuit is designed for overall conversion efficiency above 99.7%. Production-scale operators monitor the drying-tower acid temperature because a rise of 3–5°C above the design loop temperature can increase moisture carryover and accelerate catalyst degradation; this is one of the more common batch-to-batch efficiency drift points on sulfur-burning trains. Sulfur-burned acid from Shandong, Jiangsu, and Zhejiang has low arsenic and metal carryover compared with most smelter acid, but it still requires filtration or settling for sulfur ash and may contain sulfate-reducing impurities if sulfur feedstock is not maintained. Coastal sulfur-burning clusters are concentrated around liquid sulfur terminals; Shandong’s merchant acid is a short-haul supply for titanium dioxide, steel pickling, and petroleum refining, while Jiangsu and Zhejiang output is pulled by caprolactam and electronic chemical demand.

This coastal versus inland split means that the same 98.0% H₂SO₄ grade can have a different delivered impurity profile and different freight exposure. A sulfur-burned parcel from Shandong will usually contain lower arsenic than an unprocessed copper smelter parcel from Anhui, but it may carry higher road tanker cost to inland users. An inland phosphate-integrated acid parcel from Guizhou may be cheaper at the plant gate but more exposed to rail scheduling and seasonal availability.

Receiving-Terminal Compatibility and Corrosion Boundaries in Provincial Acid Transfer

Concentrated sulfuric acid is stored in carbon steel at concentrations above 93%; dilution below 90% accelerates corrosion significantly unless the tank is lined or alloyed. Receiving terminals in coastal provinces therefore check concentration, temperature, and chloride before transfer. Rail and road transport fall under UN 1830 and the Chinese dangerous goods list GB 12268; dedicated tanks are required, and residues from organic chemicals can react exothermically with strong sulfuric acid. In winter, terminals in Liaoning, Inner Mongolia, and Xinjiang must maintain tank heating or accept concentration grades that remain pumpable at lower temperatures; published data for specific terminal heat-loss calculations is limited.

For a sourcing map, the receiving condition matters as much as the production origin. A plant that ships 98.0% acid with 20 mg/kg iron can contaminate the parcel if the receiving tank previously held 92.5% acid with higher suspended solids. Dedicated or thoroughly cleaned tanks, sampling under recirculation, and lot-specific certificates are standard requirements for provincial transfers. Remote sites in Shaanxi, Gansu, and Inner Mongolia often ship smaller parcels, so buyers should verify whether the tank car fleet is dedicated to sulfuric acid or shared with other corrosive cargoes under a cleaning protocol.

Across Xinjiang, Inner Mongolia, and Gansu, smelter acid capacity remains regionally important but does not consistently enter the eastern merchant pool. Rail distances from Urumqi to Shanghai exceed 3,900 km; the rail tank car allocation is the binding supply constraint for any eastern transfer. For some remote smelter acid configurations, published data for this specific configuration is limited, and direct supplier declarations remain the only practical basis for quality risk assessment.