ENFI can provide consultation, design, EPC, project management, project supervision, project bidding, cost consultation, equipment procurement & integration, system integration and other engineering construction services, as well as the import and export of technologies, equipment and labour services for the acid-making, desulfurization, dust collection and mercury removal projects.

Business scope:

·Sulfuric acid making

Sulfur-based acid making

Smelting offgas-based acid making

Pyrite-based acid making

·Low-temperature heat recovery

·Removal of NOxSO2 from offgas (appropriate offgas desulfurization technology can be selected based on the specific offgas condition)

Desulfurization and denitration of power plant offgas - integrated catalytic desulfurization and denitration technology

Sintering offgas desulfurization and denitration of steel plant - polymer organic amine desulfurization technology

Desulfurization and denitration of various SO2-containing off-gases of non-ferrous smelter - zinc oxide desulfurization technology

Coal-fired boiler tail gas desulfurization and denitration of all sectors - sodium, ammonia, limestone (lime) / gypsum desulfurization technology

·Offgas dust collection technology and mercury removal

ENFI has rich experience in tail gas dust collection design and engineering, and is capable of offgas cooling, waste heat recovery, offgas dust collection (dust removal), dust transportation and so on.

·Waste acid recycling technology

ENFI develops the solution based on the waste acid composition and content of various acid-making systems: arsenic removal efficiency of more than 99%, to reduce the amount of hazardous and waste residue; obtains the high-purity gypsum by adjusting the pH; and obtains the available acid (about 60%) by waste acid concentration.

·R&D and supply of new materials and equipment

Through continuous R&D and innovation, ENFI introduces the advanced polymer material, composite material, alloy material and other cutting-edge technologies into the practical engineering, and develop a series of new materials and reagent products by theoretical studies, laboratory experiments, pilot tests and industrial applications.

ENFI has almost 50 years of design experience in sulfuric acid plant and offgas treatment, and have designed or contracted (by way of EPC) more than 60 sulfuric acid plants. Currently, the total production capacity of these sulfuric acid plants has exceeded 15 million t/a and the largest capacity of the plant among the commissioned plants is 2,250 MTPD. ENFI has also completed the design of several sets of desulfurization and smelting offgas desulfurization devices of power plants, and the total installed capacity of power plant offgas desulfurization device is more than 8,000 MW.

I. Project achievements in acid-making

Our goal is to achieve an optimized balance of low-cost, low energy consumption and reliable design. The acid-making process adopted is mainly the world advanced double-conversion & double-absorption process with a final conversion rate of as high as 99.8%. The interpass absorption design itself adopts 3/1 variety lending type, which allows frequent fluctuation of inlet gas concentration without sharp reduction of conversion efficiency. The change of gas flow and concentration may cause almost no impact on the final stack emission concentration. The high-efficiency catalyst is used for high gas concentration. The ratio of O2 : SO2 can be reduced as low as 0.75 and a high conversion efficiency can still be kept. Therefore, the conversion system is adaptable to a SO2 concentration of as high as 12%.

II. Project achievements in offgas desulfurization

ENFI currently has mastered the following main offgas desulfurization technologies:

·Technology of removing and recovering SO2 from the offgas with organic solution circulating absorption method

·Limestone-gypsum (wet) desulfurization technology

·Zinc oxide wet desulfurization technology

·Ammonia desulfurization technology

·Sodium desulfurization technology

III. Project achievements in offgas dust collection

Offgas dust collection projects ever undertaken by ENFI cover the non-ferrous smelting offgas dust collection involving lead, zinc, copper, nickel, magnesium, aluminum, vanadium and gold smelters, industrial boiler tail gas dust collection, power plant boiler offgas dust collection, silicon material production tail gas dust collection, gas dust collection of cement industry, as well as steel plant offgas dust collection. Until now, ENFI has contracted or designed nearly 100 sets of dust collection installation for smelters.

In recent years, ENFI has studied and improved the design of dust collection systems for separate arsenic recovery in high-arsenic gold concentrate smelting, which has achieved certain results.