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Journal of Cleaner Production 19 (2011) 2082e2087

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Journal of Cleaner Production

journal homepage: www.elsevier .com/locate/ jc lepro

Electrolytic manganese metal industry experience based China’s new modelfor cleaner production promotion

Ning Duan*, Zhigang Dan, Fan Wang, Cenxuan Pan, Changbo Zhou, Linhua JiangCleaner Production Centre, Ministry of Environmental Protection, Chinese Research Academy of Environmental Sciences, 8 Dayangfang BeiYuan Road, Beijing 100012, China

a r t i c l e i n f o

Article history:Received 24 January 2011Received in revised form9 June 2011Accepted 28 June 2011Available online 6 July 2011

Keywords:Management based CP promotional modelElectrolytic manganese metal industryTurning pointTechnology based CP promotional model

* Corresponding author. Tel.: þ86 10 8491 3945; faE-mail address: ningduan@craes.org.cn (N. Duan).

0959-6526/$ e see front matter � 2011 Elsevier Ltd.doi:10.1016/j.jclepro.2011.06.024

a b s t r a c t

Cleaner production has long been viewed as an environmental management tool in China and manyother countries. This understanding in recent years has become a major barrier that prevents CP fromplaying its full functions. This article introduces the approach, results and result dissemination ofa project set up by the central government of China aiming at controlling the serious pollution of theelectrolytic manganese metal industry. Based on experience of this project and our practical experiencesof CP audits in more than 200 companies we propose a new model for CP promotion. A preliminarydefinition of the new model is presented.

� 2011 Elsevier Ltd. All rights reserved.

1. Introduction

Since it entered China in 1992 CP has been viewed as an envi-ronmental management tool. Most of the options from CP audit(CPA) are non-low cost options. In 2007, 2008, China proposed108754 CP options via cleaner production audits. 96159 wereimplemented with a total investment of 4.58 billion USD. Theaverage investment for a single option was about 40 thousand USDonly (MEP, China, 2008,2009). Starting from the 11th five year plan,the Chinese government has classified pollution reductionscenarios into three types (the restructuring reduction, the engi-neering reduction and the management reduction) and allocatedpollution control funds to proposals according to their type ofpollution control: CP is listed in the management reduction typeand obtains the least funds.

This is also the case in many other countries like Austria, Egypt,Australia, South Africa, India, Thailand and USA, etc.. CP in thesecountries can be roughly divided into three categories: used asa pure environmental management system or most CP options arenon-low cost options (Hamed and Mahgary, 2004); found to focuson improvements over peripheral devices or minor technologieslike lighting and air-conditioning in offices (van Berkel, 2007); andexcessively working with very small companies (Koefoed andBuckler, 2008; Rathi, 2003; Chavalparit & Ongwandee, 2009). It isin this sense they can all be called management based CP.

x: þ86 10 8493 2378.

All rights reserved.

CP in these countries has three features in common: first,compliance with the laws is not addressed in audit procedures;second, large scale and complex equipments generating the mostpollution of the companies are not tackled; emphases are placed onrelative terms instead of absolute terms (i.e. how much profits areobtained with how little investment vs total profits made).

For China the 1990’s was a special decade during which it’s CPreceived concentrated assistances from international communities.UNEP, UNIDO, UNDP, the World Bank, Asian Development Bank,Canada, USA, the Nederland and so on, all donated technicalassistance projects to China for its CP promotion. These projectsconducted CP audit in Chinese companies and helped China culti-vate its core face to conduct CPA. While CP saw a lot of successfulstories in China authors of this paper, as director and core staff ofthe Cleaner Production Center of China’s Ministry of EnvironmentalProtection and China National Cleaner Production Center of UNIDO/UNEP National Cleaner Production Center Program, frequently runinto a situation where CPA has brought significant benefits tocompanies but governments don’t think it important, and moreseriously, in many cases companies are not willing to constantlyand actively conduct CP if without outside assistance. The reason isquite clear: now that CP does not solve the biggest problem that wecare the most, why should we spend resources promoting it?

This has to do with the name of cleaner production. At leastliterally the only thing that is important is becoming cleaner thanbefore, no matter if the companies meet environmental standards.This is perhaps right in the States where CP originated and in manyother developed countries. In the US CP came out after the

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 20100

500

1000

1500

2000

2500

Qua

ntit

y(1,

000

tons

)

Time (year)

Capacity Output Exports

Fig. 1. Production and export of China’s electrolytic manganese metal from 1990-2009.

N. Duan et al. / Journal of Cleaner Production 19 (2011) 2082e2087 2083

“compliance era” (Miller et al., 2008). However today in Chinaadvanced and backward technologies co-exist, a huge number ofcompanies are using backward technologies. For the plants thatgenerate too many pollutants at high concentrations exceedingenvironmental standards many times, there are no non-low costoptions that could allow them to meet environmental standards.Our 18-year’s practice in CP projects, international and domestic,shows that in a plant using backward technologies, in general, thenon-low cost options at maximum can reduce pollution by 20% atthe audit focus (the workshop or the production line that is beingaudited). A 20% reduction in pollution however does not enable thiskind of plants to meet environmental standards.

A huge number of papers proposed numerous renovations in CPpromotional models, for example, efforts to combine cleanerproduction audit with environmental management systems(Fresner, 1998) or with environmental management accounting(Gale, 2006). Recent work probed advantages in integrating moretools to help implementation of desired changes at all levels ofa company management pyramid (Palmar De and Dobes, 2010).

Fig. 2. Electrolytic manganese

While obviously effective for helping companies in Austria andEurope, these management based CP models do not solve theproblems we encountered in China.

We in this paper present a new CP promotional model based ona project we conducted in electrolytic manganese medal industry.The biggest difference of this model from the management basedCP model is its core is to develop and install practical CP high-techsthat are aiming at changing major production process and equip-ment starting from a traditional CP audit.

2. CP experience in China’s electrolytic manganese metalindustry

2.1. The electrolytic manganese metal industry

2.1.1. Production and technologySince 2000, China has become the largest producer, consumer

and exporter of electrolytic manganese metal (EMM) in the world.Fig. 1 summarizes major data of China’s EMM industry in previousyears. China’s EMM production capacity reached 2.11 million tonsand its actual production reached 1.31 million tons in 2009. Withrhodochrosite as its main raw material, China’s EMM industry stilluses hydrometallurgical technology developed by the Bureau ofMines U.S. (Brantley and Rampacek, 1968). In over 50 years, themain technology producing EMM has remained unchanged withpart of its technological parameters improved (Fig. 2).

2.1.2. Environmental problemsAn overdose of manganese results in severe nerve dysfunction

and movement dysfunction (U.S. ATSDR, 2000; IEH, 2004). Highconcentrations of manganese in residue constitute huge potentialenvironmental risks (Xin et al., 2011). Moreover, selenium added tothe production process is harmful to human health (Hagelstein,2009). Since 2000, the rapid increase in EMM output in China hascaused severe environmental pollution. According to data fromlocal monitoring stations, in some rivers in areas where EMMplants were concentrated, in 2005, the most polluting period,concentrations of total manganese and ammonia nitrogen

metal production process.

Fig. 3. Operation site in electrolytic manganese metal plant ((a) Passivating cathodes, (b) Discharging filter cake, (c) Residue landfill.

Fig. 4. Flowchart of post-electrolysis process.

N. Duan et al. / Journal of Cleaner Production 19 (2011) 2082e20872084

exceeded 10 times and 50 times, respectively, the limiting valuesspecified in the 3rd class national standard for surface waters;today the situation has greatly improved, but the manganese andammonia nitrogen concentrations in the rivers still exceeds thestandards.

2.2. Needs for CP high-tech

In order to put the severe pollution under control the centralgovernment of China set up a project entitled “Pollution preventionmeasures and demonstration for electrolytic manganese metalcompanies in Mn Delta.” In 2006 CP audits were carried out at 5 ofthe 10 biggest EMM companies and at many medium sized ones(Duan et al., 2010). During and after the audits numerous non-lowcost CP options were implemented, including strengthening waterconsumption management (i.e. bonus of workers of any workshopwould be reduced if their workshop discharged more wastewaterthan the quota specified to the workshop); enhancing ore samplingand putting in ores strictly based on the sample analysis; checking

Fig. 5. Equipment for process waste wate

andmaintainingmachines regularly; and so on. As demonstrated inFig. 3, pollution in these areas is generated largely by backwardtechnologies. Actual data from these companies show these non-low cost options at most reduced 10% of their pollution. Theseaudits identified importance of developing three CP high-techs, asexplained in the next section.

2.3. CP high-techs for EMM industry

2.3.1. Process waste water whole process control technologyFig. 4 provides a detailed flowchart of the post-electrolysis

process of the EMM industry. Cathodes are taken out manuallyfrom the electrolysis cell and passivation tank. A large amount ofelectrolyte and passivating liquid drops on toworkers and becomespart of the process waste water. In the washing process, the cath-odes are washed directly with high pressure running water.A 30000 t/a EMM plant generates 300 m3 d�1 of waste water(Mn: 2000 mg L�1, Cr6þ: 300 mg L�1, NH3eN 13000 mg L�1).Workers are directly exposed to waste water droplets.

r whole process control technology.

Fig. 6. Process of double-leaching technology.

Fig. 7. Demonstration line of double-leaching technology.

N. Duan et al. / Journal of Cleaner Production 19 (2011) 2082e2087 2085

The process waste water whole process control (PWWWPC)technology adopts a couple of high-tech methods. Althoughcounter-flow washing is a traditional CP technology, its waterconsumption is still too large to be recycled back to the productionprocess. By adopting the needle jet technology, the PWWWPCtechnology saves a lot more water: an 80% saving in fresh waterconsumption. “Hanging and dropping” was found to be able torecover the electrolyte and electroplating solution many years agoin numerous CP audits. However, due to many human operationsrequired it has not been popularized. With precise laser positioning

Fig. 8. Flowchart of manganese residu

and use of a manipulator, the PWWWPC technology puts thisconcept into practice. Its operational error is no more than 2 mm ina production line of 10e20 m in span and 60e80 m in length. Withthe adoption of these high-tech methods, the PWWWPC tech-nology is able to reduce the electrolyte and passivation liquidcarried out by cathodes by 65% or more, and realize complete reuseof process waste water and the chemicals contained in it (Fig. 5).

2.3.2. The double-leaching technologyAt present, the residue generated by the filter press contains

3.0e4.0% Mn and 3.0e4.0% (NH4)2SO4. Although solid/liquidseparation technology has an even longer history than the “hangingand dropping” CP measure, and many attempts have been made todevelop technology to recover manganese from the residue, theseattempts have all failed because these technologies were built onthe frame-type filter and they all used water in leaching. Frame-type filters are cheap but backward. Using water in leachingresults in “water swelling”, thus, stopping the electrolysis process.

The double-leaching technology is built on a membrane filterpress that is new in solid/liquid separation equipment. It is basedon the membrane filter press a new control system is designed tosuccessfully use anolyte in leaching, and use the filter press asa chemical reactor, which improves the diffusion process betweenthe solid/liquid phases. Returning the spent anolyte to themembrane filter press not only leaches out the manganeseremaining in the residue one more time but also saves waterconsumption asmuch as possible. With proper modifications to thetraditional production processes this technology (Figs. 6 and 7) iscapable of recovering 50% of acid-dissolvable Mn and 30% of(NH4)2SO4 from the residue.

e-based brick-making technology.

Fig. 9. The machine used for manganese residue-based brick-making technology.

Table 1Environmental and economic benefits of CP high-techs for electrolytic manganese metal industry.

Items PWWWPC technologyfor 30000t EMM/a plant

Double-leaching technologyfor 30 000t EMM/a plant

Manganese residue-basedbrick-making technologyfor 30 million pieces ofstandard bricks/a

Environmental benefitsWaste water reduction (t/a) 62000 e e

Fresh water reduction (t/a) 27000 e e

Resources recovery/pollutionreduction (t/a)

Mn: 300 Mn: 3600 Manganese residue: 20000Cr6þ: 86 NH3-N: 1518 Mn: 800 NH3-N: 188

Economic benefitsTotal investment (million USD) 3.53 2.65 1.18Sales income (million USD/a) 1.87 2.69 1.23Net profit (million USD/a) 1.06 1.75 0.58Net Present value (million USD) 5.95 11.15 8.14Inner rate of return on

investment (%)42.3 82.9 58.2

Payoff period (year) 3.5 2.4 2.9

Notes: USD $1 is approximately equivalent to 6.8 Yuan.

N. Duan et al. / Journal of Cleaner Production 19 (2011) 2082e20872086

2.3.3. Manganese residue based brick-making technologyResidue, in solid state, is the largest and most dangerous waste

of this industry. For every metric ton of its product the EMMindustry discharges 8e10 metric tons of residue. Technologiesaimed at reusing the residue like using the residue in cementretarder and complete nutrient fertilizer have been developed inthe last two decades. Because the amount of residue added toproducts is so small these technologies have not yet had anindustrial application. Compared with brick-making using coal-burning slag or steel slag, it is much more difficult to use manga-nese residue to make bricks. The activity of coal-burning slag andsteel slag is high but it is low in manganese residue, since the SiO2and Al2O3 contents in the former are higher than 60%, compared tothat of the manganese residue which is lower than 30%. Moreover,the viscosity of the residue is far higher than coal-burning slkag andsteel slag, therefore, it is hard to spread it evenly. Besides, itschemical composition is complicated containing many toxic andhazardous substances (Zn, Cu, Pb, Cd, Cr, etc.)

In the manganese residue-based brick-making technology,a specific pretreatment technology has been developed whichsolidifies the soluble manganese and heavy metals and drivesammonia nitrogen out for recovery. A dedicatedly manufactured

equipment disperses the residue evenly. The technology (Figs. 8and 9) is capable of adding 30% or more of the residue to thebricks being made. The building material quality, toxicity charac-teristics leaching and radioactivity of the bricks all conform to therelevant national standards. Application of this technology mayprovide a way of resolving the environmental problems related tothe residue from the EMM industry at its source.

2.3.4. Environmental and economic analysisThe 3 technologies enable EMM industry tomeet environmental

standards steadily and bring obvious economic benefits to thecompanies (Table 1). More importantly, they prevent workers frombeing exposed to harmful working environments, and simulta-neously increase the auto-control level and modernization level.Having just been developed these technologies have beenpurchased by 9 plants 12 times in less than two years. 5 of the 10largest EMM plants in China have signed contracts to buy thesetechnologies.

The three CP technologies have been published in the List ofNational Advanced Pollution Prevention Demonstration Technologies

issued by the Ministry of Environmental Protection, and in theImplementation Options of CP Technology issued by the Ministry ofIndustry and Information Technology. These technologies are madepublic and recommended nationwide. If the EMM industry appliesthe process waste water whole process control technology and thedouble-leaching technology to 100% of its capacity, and applies thebrick-making technology to 20% of its capacity, based onproductionin 2009, the industry will per year reduce waste water discharge by2.7 million metric tons, reduce residue by 4 million metric tons,reduce and recover manganese, potassium dichromate andammonia nitrogen by 170,000 metric tons, 3747 metric tons and66,000 metric tons, respectively.

3. Conclusions

Having promoted CP for almost 20 years, China is now facinga turning point. China has gained enormous benefits from devel-oping and popularizing CP. However, relying on the non-low costCP option model excessively for so long, China now needs todevelop a new model, since not enough actual cases are being seeninwhich non-low cost CP options allow Chinese companies tomeetenvironmental standards. To recover CP momentum and to meet

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China’s real needs today it is time to adopt a newmodel to promoteCP: a technology based CP promotional model, not a managementbased CP promotional model.

It is worth pointing out the technology based CP promotionalmodel does not exclude the traditional CPA. The technology basedCP promotional model actually starts with CPA since it is throughCPA that the technology based CP promotional model identifies themost polluting areas, the practical technology needs and theenvironmental standards that apply. It is also through CPA (goodhousekeeping procedures, etc.) that the CP high-techs can be betterused and maintained. In addition CPA is a powerful tool for theenterprises that already compete with regulations to go beyondthem whenever still feasible.

Based on these a preliminary definition for the technology basedCP promotional model can be summarized as follows: ① itsprimary goal is to meet environmental standards,not to make thecompany cleaner; ② its core part is to develop and install CP high-techs to replace/change the major production process and equip-ment that generate the most pollution and not the peripheral orminor devices; ③ the initial step in R&D for its CP high-techs is toidentify the most polluting areas via a CP audit procedure; ④ itsdevelopment approach in most cases is research into technologiesthat modify/improve high-techs that have proven practical use inother sectors, and not a completely brand new technology; ⑤ itsfocus in R&D is solve technological difficulties caused by trans-ferring and integrating available high-techs and not the funda-mental issues such as basic theories, new materials, or radicalprocess changes; ⑥ it adopts the CP high-techs that allowcompanies to meet standards quickly and not in a long time.

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