Resources, Conservation and Recycling 54 (2010) 171–177

Contents lists available at ScienceDirect

Resources, Conservation and Recycling journal homepage: www.elsevier.com/locate/resconrec

Substance flow analysis of zinc in China
Guo Xueyi ∗ , Zhong Juya, Song Yu, Tian Qinghua
School of Metallurgical Science & Engineering, Central South University, South Street of Yuelu, 932, Changsha, Hunan 410083, China

article

info

Article history:
Received 16 January 2009
Received in revised form 23 July 2009
Accepted 26 July 2009
Available online 28 August 2009
Keywords:
Zinc
Substance flow analysis
“STAF” model
Life cycle
Resource recycling

abstract
A material stock and flow (STAF) model was constructed to track the pathway of zinc in China, 2006, for the study of the industrial metabolism of a certain metal within a regional level. The primary flows of zinc include production, fabrication and manufacturing, use, and waste management. This paper traces the major flows of zinc from ore, to product, to potential secondary resource as it moves through the
China’s economy over 1 year, and inventory data, and mass balance equations were used to determine the quantity of flows. The domestic ore produced was 3248.3 Gg and output of refined lead ingot was
3162.7 Gg in 2006. It was calculated that, in the production and manufacture and fabrication stage, the self-supply efficiency of zinc raw materials in 2006 is 87.58% and 94.92%, respectively. The results reveal that China has richer zinc raw resources. But only about 3.68% and 9.06% of the discarded zinc in the two stages were recycled, respectively. While zinc’s residence time can be high for many of its applications in the building and construction sector, since the majority of zinc is used as an anti-corrosion coating, there are dissipative losses occurring during the lifetime of products and infrastructure containing zinc.
This study and others suggest that zinc losses to the environment are significant in magnitude, and their impacts should be evaluated over time and at various spatial scales. In addition, the results of this study and other element and material flow analyses can help guide resource managers, environmental policy makers, and environmental scientists in their efforts to increase material recovery and recycling, address resource sustainability, and ameliorate environmental problems.
© 2009 Elsevier B.V. All rights reserved.

1. Introduction
The method of substance flow analysis (abbreviated as SFA) provides a helpful tool for the study of the industrial metabolism of a certain metal within a regional level. At present the SFA have been studied a lot in some developed countries, such as German,
Denmark and so forth, with providing suggestions for the country and relevant industries. Country and continent level material cycles have been carried out for various substances, including copper
(Daigo et al., 2009), lead (Hansen and Lassen, 2003), zinc (Spatari and Bertram, 2003), and a number of others. This paper traced the stocks and flows of zinc over a 1-year period in China, 2006, in the same way, the SFA of zinc in other years (1998–2005) analyzed.
Zinc is one of the important metals in national economic development in China. The main existing states of zinc in nature are sulfide and oxide. Minerals from which zinc is extracted include sphalerite (zinc sulfide), smithsonite (zinc carbonate), hemimorphite (zinc silicate), and franklinite (a zinc spinel). There are two kinds of routes available for zinc production, i.e. hydrometallurgi-

∗ Corresponding author. Tel.: +86 731 8836207; fax: +86 731 8836207.
E-mail address: xyguo@mail.csu.edu.cn (X. Guo).
0921-3449/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.resconrec.2009.07.013 cal method and pyrometallurgical method. The hydrometallurgical methods include high-pressure leaching, fluid-roasting plus leaching. The pyrometallurgical methods include reduction-distillation, imperial smelting process (ISP). The metallic zinc is finally produced by either distillation or electro-winning.
Zinc is the fourth most common metal in use, trailing iron, aluminium, and copper in annual production. Zinc has a good drawability, anti-corrosion property and wear resistance, and is widely used in metallurgy, building materials, light industry, mechanical and electrical, chemical, automotive, military, coal and oil industries and sectors. Most of the produced zinc is used to galvanize or parkerize steel and iron products to prevent corrosion. Zinc combines with some other non-ferrous metals to form alloys, for example, the alloy composed by aluminum, zinc and copper is widely used in die casting, while the brass composed by zinc, copper, tin and lead is used for the mechanical manufacturing industry.
The zinc plate containing a small amount of lead, cadmium and other elements produces anode of Zn–Mn dry cells, printing zinc plates and offset printed panels. Zinc fertilizer (zinc sulfate, zinc chloride) is helpful for the plant cell respiration and carbohydrate metabolism. Zinc powder, lithopone, zinc chrome yellow can be used for pigment, and zinc oxide used for medicine, rubber, paint, and other industries (Liang, 2004; Spatari and Bertram,
2003).

172

X. Guo et al. / Resources, Conservation and Recycling 54 (2010) 171–177

Fig. 1. Life cycle stages of zinc and zinc alloys.

Zinc plays a role in the regulation for the human body’s immune function, and promotes the normal development of children and healing of ulcers. However, in some cases, zinc has a certain degree of hazard on the human body. For example, the smoke of zinc oxide formed by inhalation-zinc at a high temperature will cause metal fume fever.
The extensive use and consumption of zinc in industrial production and social life promote the rapid development of zinc industry, and this made zinc the third largest non-ferrous metals in the world.
This work has studied the substance flow analysis of zinc in the past several years, in order to explain the situation of the flow and recycling of metallic zinc, and would provide guidance for the high-comprehensive utility of zinc resource.
2. SFA module of zinc
In the “STAF” model, the substance flow analysis of zinc comprises four primary components: production, fabrication and manufacture, use and waste management. These processes can be divided into several branch processes, e.g. the stage of production includes mining, milling, smelting and refining (Guo and Song,
2008).
Fig. 1 (Harper and Bertram, 2003) shows the life cycle of zinc, which involves the four main processes and several branch processes, and all the substance flows connecting them together, while the loss into the biosphere is not included (Guo and Tian, 2008;
Cohen, 2007).
The production and consumption of zinc ingot are listed in
Table 1 (The Editorial Committee of Non-ferrous Metals Industry
Yearbook of China, 2007).
In 2006, Chinese domestic zinc ore output was 2844.2 Gg/year
(the content of metallic zinc, the same in the following text if not

other specially stated), which includes the zinc content in zinc ores, concentrates and mixed zinc ores; the output of the refined zinc ingot in 2006 was 3162.7 Gg/year (The Editorial Committee of Nonferrous Metals Industry Yearbook of China, 2007).
The data of imported/exported zinc concentrate, scrap and products are listed in Table 2 (The Editorial Committee of Non-ferrous
Metals Industry Yearbook of China, 2007). It can be seen from the table that both the amounts of imported concentrate and unwrought zinc are quite large, while most of the concentrates are from domestic and the exported quantities can be ignored.
2.1. Production of zinc
The production of zinc includes three main processes: mining, smelting and refining. The main material inflow of the mining stage is ore, while the outflows are zinc concentrates and tailings. The data of mineral production throughout the country were obtained

Table 1
The production and consumption of zinc ingot in China (The Editorial Committee of
Non-ferrous Metals Industry Yearbook of China, 2007), 2002–2006 (Gg/year).
Project

2002

2003

2004

2005

2006

Mined zinc production
Zinc ingot production
Zinc ingot consumption
Imported zinc ingot
Exported zinc ingot

1624.1
2155.1
1676.1
68.4
472.8

2029.1
2318.5
2318.2
136.0
451.0

2391.2
2719.5
2551.2
239.5
224.2

2547.8
2776.1
2989.0
392.2
123.3

2844.2
3162.7
3115.3
318.2
325.4

Data resource: “China Nonferrous Metal Industry Yearbook 2005–2007”. The zinc ingots are produced by smelters and refineries. They include the output of imported semi-products originated from the raw materials of various types (such as ores, concentrates, leaching residue or scrap), in which the re-smelted zinc and zinc powders are not involved.

X. Guo et al. / Resources, Conservation and Recycling 54 (2010) 171–177
Table 2
The data of import and export zinc, old scrap and zinc products, 2006 (trade volume,
Gg/year).
Project

Export volume

Import volume

Concentrate
Unwrought zinc and its product
Refined zinc
Zinc alloy
Zinc scrap
Manufactured good
Products
Zinc oxide
Zinc white

–
341.5
325.4
16.1
0.3
48.6
32.5
65.1
62.6

828.4
532.1
318.2
213.9
72.5
5.0
72.0
26.5
0.23

Data resource: “China Nonferrous Metal Industry Yearbook 2007”. The amounts of zinc concentrates, zinc scrap and zinc oxide are that of trade volume. The zinc content of zinc alloy and zinc oxide is 80%; the zinc content of concentrate is 55%.

from the statistical reports, while the zinc content in the tailings was calculated by experiential formula, and the net trade amount of concentrate was derived from the statistical reports of metal trade (Gordon and Graedel, 2003).
Zinc scrap was from primary resources and secondary resources.
The zinc ingots produced by primary resources are relative with the scrap flow, which was calculated by the experiential formula.
The scrap used in the production of recovered zinc was divided into old scrap and new scrap (from the fabrication and manufacture and waste management, respectively) in the regional level. In the country level, only the old scrap was taken into account, from the stage of waste management, while the new scrap was not quantified. The net trade amount of zinc ingots was calculated from the statistical reports of metal trade, and the net amount of exported zinc was an outflow of the production stage, while its net imported amount was an inflow of the fabrication and manufacture stage (Qiu and
Yiqian, 2005).
Zinc flows into and out of the stage of fabrication and manufacture in the form of zinc ingot. The change of stock in the stage of zinc production was calculated by the following formula: the change of stock = production + imported amount
− exported amount − used amount
In China, the inflows of zinc in production stage are domestic ores and imported ores, while the outflows are mainly refined zinc, tailings, slag, and the metal loss in production process.
The domestic output of mined zinc was 2844.2 Gg in 2006. The contents of zinc in the tailings and slag were 404.1 Gg and
151.9 Gg, respectively, which were calculated based on the efficiency of dressing (87.56%) and smelting (94.66%) (The Editorial
Committee of Non-ferrous Metals Industry Yearbook of China,
2007). From the output of mined zinc and tailings, the zinc content of domestic concentrates in China, 2006, was calculated as follows:
2844.2 + 404.1 = 3248.3 Gg. In addition, the 455.6 Gg imported concentrates (the zinc content in the trade volume of net imported concentrates: 828.4 × 55% = 455.6 Gg) produced 24.3 Gg slag after smelting, so, there is 176.2 Gg slag totally in production.
2.2. Manufacture and fabrication of zinc
The new scrap produced flows out of the manufacture and fabrication stage in three ways: flowing into the stage of production
(for the production of recovered zinc); and flowing into the stage of fabrication and manufacture (for the re-smelting or direct use); flowing into the stage of waste treatment (as the harmless or harmful industrial waste, IW and HW).
With assuming that the new scrap produced in the manufacture and fabrication stage did not participate in the trade activities

173

among the regions, only the new scrap flowing into the production stage and the stage of fabrication and manufacture were taken into account in the regional level.
The new scrap was generally analyzed firstly in the main application of zinc in the manufacture and fabrication. It was estimated that the new scrap re-flowing into the manufacture and fabrication stage were the scrap of brass, bronze and other semi-products. The new scrap entering the production stage is equal to the difference between the new scrap for recycling and that re-flowing into the manufacture and fabrication stage. Outflow of zinc as IW and HW entering the waste management stage is equal to the difference between the total output of the new scrap and the recovered scrap
(Zhang and Lu, 2007).
The substance flow of zinc from the production stage into the manufacture and fabrication stage is a branch of the outflows of the production stage, while the substance flow of zinc from the stage of manufacture and fabrication into waste treatment stage is a branch of the inflows of the waste management stage. The substance flow of zinc from the manufacture and fabrication stage into the use stage is equal to the difference between the inflows and outflows of the manufacture and fabrication stage (Luo, 2005).
2.3. Use of zinc
The substance of zinc flows from the manufacture and fabrication stage into the use stage. A part of these flows into the following stage of waste management in the form of wastes, and the substance stock of zinc in use stage is equal to the difference between the inflows and outflows in this stage.
The use of anti-corrosion always ranks first in all the application of zinc in the consumption structure around the world, followed by the zinc products (die casting, processed products), and zinc used for the preparation of zinc alloy. As far as the industrial field was concerned, the use of construction (as galvanized zinc) almost takes up one-third of the total utilization of zinc, followed by transport and electrical engineering, mechanical engineering and other fields.
In the case of zinc consumption in China, the major fields of zinc consumption are as follows: galvanized zinc, zinc alloy, Zn–Mn batteries, and copper alloy and so on as shown in Table 3. The ratio of various zinc products to consumption structure of China was: galvanized zinc 40%, batteries 18%, zinc oxide 16%, copper products
13%, zinc alloy 12%, and the other 1% (Shang and Ruan, 2006; Gui,
1999).
2.4. Waste management of zinc
The old scrap produced in the waste management stage was sent back to the production stage and the manufacture and fabrication stage. In the stage of production, the amount of old scrap flowing into from the waste management stage is equal to the difference between the calculated value of zinc used for the production of recovered zinc and the estimated value of zinc scrap flowing into the stage.
The amount of recovered zinc is less no matter recycled from imported resources or from the domestic secondary resources. The imported zinc scrap is not imported as “zinc scrap” but the form of mixture with other scrap metal, in which zinc scrap is not apparent.
Table 3
The consumption of zinc in China, 2003–2005 (Gg/year).
Year

Galvanized zinc Battery

Zinc oxide

Copper products Alloy

Other

2003
2004
2005

828
952
1188

373
428
535

331
381
475

386
309
386

248
286
356

207
238
297

174

X. Guo et al. / Resources, Conservation and Recycling 54 (2010) 171–177

Table 4
The consumption and production of zinc scrap in China, 2002–2006.
Project

2002

2003

2004

2005

2006

Domestic zinc ingots output (Gg/year)
Domestic recovered zinc scrap (15% of the zinc ingots output)
Domestic recovered zinc output (Gg/year)
Ratio of recovered zinc to zinc ingot output (%)
Ratio of recovered zinc to the amount of recycled zinc scrap (%)

2155
323
21
1.0
6.5

2319
348
32
1.4
9.2

2719
408
45
1.7
11.0

2776.1
416
50
1.8
12.0

3162.7
474
57
1.8
12.0

Data resource: “Statistics of Nonferrous Metal”.

The scrap alloy is the main raw materials of domestic recovered zinc. The zinc consumed in other fields is hardly recycled (such as zinc in Zn–Mn batteries).
Before calculating the recycled alloy scrap, it is assumed that: firstly, the average life of zinc alloy is generally 10 years, and the recovery efficiency of zinc alloy in the payback period is 90%. Secondly, 20% of the zinc used for the production of alloy is taken as recyclable scrap, which is effectively recovered. The zinc with low value is difficult to be recycled; therefore, the recovery situation of zinc is not as good as that of copper and aluminum. In addition, as most of zinc scrap is occupied by workshops of small scale, which is unable to enter the valid statistics. Therefore, the statistics amount of recovered zinc production is actually much lower than the theoretical amount (Jiang, 2004).
Due to poor recovery of zinc, the production of recycled zinc in China is rather low (about 50,000 t annually), and this value can be ignored in the total amount of the refined zinc (Ma, 2002).
Table 4 shows the production and recovery of zinc scrap in China,
2002–2006.
3. The SFA of zinc in 1-year cycle
Fig. 2 shows the zinc cycle of China in 2006, in which the data was collected from above.
According to the data above, some primary indexes can be calculated as following.
3.1. The ratio of domestic substance flows in the inflows and the proportion of scrap in the production and manufacture and fabrication The substance flows into the zinc production are as following: the domestic ores 3248.3 Gg/year, the imported concentrates
455.6 Gg/year, the domestic new scrap 120.0 Gg/year (all of the old and new scraps in production except imported scrap:

78.4 + 63.3 − 21.66 = 120.0 Gg/year), and the imported new scrap
21.66 Gg/year (half of the total imported scrap).
So the ratio of domestic substance flow into the production Pz is: Pz =
=

3248.3 + 120.0
× 100%
3248.3 + 455.6 + 120.0 + 21.66
3368.3
× 100% = 87.58%
3845.6

And the ratio of zinc scrap in the inflows of the production Ps is:
Ps =
=

120.0 + 21.66
× 100%
3248.3 + 455.6 + 120.0 + 21.66
141.66
× 100% = 3.73%
3845.6

The substance inflows of the manufacture and fabrication are as following: the domestic refined zinc 3162.7 Gg/year, the net imported refined zinc (alloy) 190.6 Gg/year, the net exported zinc and zinc products 26.3 Gg/year, the domestic old scrap in direct use 309.78 Gg/year (domestic new scrap and old scrap), and the imported old scrap in direct use 21.66 Gg/year.
So the ratio of the domestic substance flows in the inflows of the manufacture and fabrication Mz is:
Mz =
=

3162.7 + 309.78
× 100%
3162.7 + 190.6 − 26.3 + 309.78 + 21.66
3472.48
× 100% = 94.92%
3658.44

And the ratio of zinc scrap in the inflows of the manufacture and fabrication Ms is:
Ms =
=

309.78 + 21.66
× 100%
3162.7 + 190.6 − 26.3 + 309.78 + 21.66
331.44
× 100% = 9.06%
3658.44

Fig. 2. The zinc cycle of China, 2006 (Gg/year). According to the references, the grade of tailing is 0.57%; the ratio of zinc in imported zinc concentrate is 55%; the ratio of zinc in slag is 5.6%; the ratio of zinc in zinc scrap is 60%; the ratio of zinc in alloy and zinc oxide is 80%; the ratio of zinc scrap produced to manufacture and fabrication is 10%; the ratio of direct and indirect use of old scrap both are 50%; the efficiency of mining is 87.56%; the efficiency of smelting is 94.66% (Non-ferrous Metal Statistics, 2003–2007).

X. Guo et al. / Resources, Conservation and Recycling 54 (2010) 171–177

175

Table 5
The zinc ore resource productivity of China in 1998–2006.
Items

1998

1999

2000

2001

2002

2003

2004

2005

2006

Production of refined zinc (Gg/year)
Zinc ores output (Gg/year)
Domestic zinc ores output (Gg/year)
Net imported ores (Gg/year)
Zinc ore resource productivity (t/t)

1486.3
1273
1611.1
−68.8
0.96

1703.2
1476
1830.3
−87.1
0.98

1957
1780.3
2046.3
−27.5
0.97

2037.6
1693.2
1946.2
292.4
0.91

2155.1
1624.1
1866.8
357.5
0.97

2318.5
2029.1
2332.3
350.2
0.86

2719.5
2391.2
2748.5
338.9
0.88

2776.1
2547.8
2856.3
312.3
0.88

3162.7
2844.2
3248.3
455.6
0.85

3.2. The index of ore

4. Analysis of index

The index of ore R is the ratio of the refined zinc (RZ) to the demanded zinc ores (DZO) of the zinc industry in the cycle. It can be used to measure how much the zinc ores resource depends on zinc industry. The index R is defined as follows:

As shown in Table 5 (Zhao, 2001; Di, 2002; Lei, 2002, 2003a,b;
Shi, 2004; Wang, 2004; Wu and Wu, 2005; Peng, 2005a,b; Wu,
2007), the amounts of refined zinc, domestic zinc ores and net imported zinc of China all have increased since 1998–2006. However, the amount of net imported zinc exhibited the minimum value in 1999, and this means that the higher production of refined zinc was achieved with the less mineral resources, resulting in the highest value of ore resource productivity of zinc in 1999.
In addition, the production of refined zinc in China has increased annually since 2000–2006. However in 2002, Chinese output of domestic zinc ores got the minimum value while the net amount of the imported ores got the highest value. The total amounts of mineral resources for zinc production in those years were relatively stable, thereafter resulting in relatively stable for resource efficiency of zinc. Compared to 1998, the increase of the net imported zinc ores was much larger than that of the domestic ores in 2006, which implies that the demand for zinc ores has greatly increased in recent years, however, the domestic capacity of mining can hardly satisfy the demand, so the difference between the production and the demand requires the large amount of the imported zinc ores.
Fortunately, because of the relatively sufficient output of domestic zinc ores, the proportion of net imported ores in supply of total zinc resources of China is still rather small.
Table 6 indicates that from 1998 to 2006, the indexes of Pz , Ps , RP and S exhibits a general tendency of decrease, which implies that, the imported ore in zinc production of China occupies a certain ratio, while the recycling efficiency of zinc scrap has not significant increase, and the ratio of scrap utilization in the raw materials for zinc production present a decrease tendency, so more attention should be paid on strengthening of scrap resources recycling from the research and practice of non-ferrous metals industry. Although at present, the output of domestic zinc ores in China may meet the demand of domestic production and consumption in certain degree, in the long term, the zinc industry of China will also face with the severe problem on resource depletion. With the understanding of the reality, increasing the recycling efficiency of zinc secondary resources is an essential way to the sustainable development of zinc industry in China.
In addition, due to the rapid development of the national economy, the demand of zinc resources has increased by the average rate of 15.22% in recent years, which is lower than the production of refined zinc, but higher than that of domestic ores supply
(Zhou, 2003). So the ratio of domestic concentrates quantity in the total supply of zinc resources goes downward. Under the pressure of consumption demand, increasing the productivity of the mineral resources exploitation, ore dressing and refining is an efficient measure for promoting zinc industry of China toward sustainable development. At present, how to increase the resource efficiency is a significant issue for zinc industry of China. Based on the result, several suggestions are proposed as follows:

R=

RZ
DZO

In China, the domestic ores contribute zinc 3248.3 Gg/year to zinc production, while the net imported concentrates 455.6 Gg/year, so the index R of China in 2006 is:
R=

3248.3 + 455.6
= 1.1711 t/t
3162.7

The result is equal to putting 1.1711 t zinc concentrates into the production of 1 t refined zinc.
3.3. The index of zinc physical trade balance
Physical trade balance (PTB) measures the surplus of economic trade on a certain substance, which is equal to the difference between the imported and the exported volumes. So:
The PTB of the zinc concentrates in China, 2006 is: 828.4 − 0 = 828.4
(Gg/year).
The PTB of the zinc scrap in China, 2006, is: 72.5 − 0.3 = 72.2
(Gg/year).
3.4. The recourse productivity of ores
In order to measure the efficiency of substance application, the index of resource productivity (RP) is introduced into the substance flow analysis of zinc industry. It is defined as following: resource productivity (RP) =

gross domestic product (GDP) direct material input (DMI)

This index, which is the reciprocal of the ore index, is calculated in unit of t/t. So the ore resource productivity of zinc is about 0.8539 t/t in China, 2006.
3.5. The index of zinc scrap
The index of zinc scrap S is the criterion to measure how abundant the scrap resource is in the zinc industry. The larger the S is, the more abundant the scrap resource is; while the decrease of S shows the short of scrap resource. The index S is defined as follows:

S=

DOS + DNS
RZ

The domestic old scrap (DOS) put into the production is
56.74 Gg/year in China, 2006, and that of domestic new scrap (DNS) is 63.3 Gg/year, so the index of zinc scrap is:
S=

56.74 + 63.3
120.0
=
= 0.0380 t/t
3162.7
3162.7

(1) Exploration and exploitation of new zinc mines.

176

X. Guo et al. / Resources, Conservation and Recycling 54 (2010) 171–177

Table 6
Indexes of production and manufacture and fabrication, and consumption in China, 1998–2006.
1998

1999

2000

Production
Pz (%)
Ps (%)
R (t/t)
RP (t/t)
S (t/t)

104.9
4.63
1.038
0.96
0.046

104.2
4.83
1.024
0.98
0.046

100.7
4.76
1.032
0.97
0.045

Manufacture and fabrication
Mz (%)
Ms (%)

120.2
10.93

127.0
11.41

125.5
11.32

2001
87.1
4.41
1.099
0.91
0.046
121.8
11.05

2002

2003

84.0
4.49
1.032
0.97
0.041
112.6
10.44

86.7
3.87
1.157
0.86
0.038
107.3
10.13

2004

2005

2006

88.8
3.74
1.135
0.88
0.036

89.83
3.91
1.141
0.88
0.038

87.58
3.68
1.1711
0.85
0.038

97.1
9.36

93.98
9.08

94.92
9.06

Average (%)
92.63
4.25
1.0921
0.92
0.0416
111.15
10.31
Incremental change (%)

Consumption
Consumption (Gg)
Ratio of domestic zinc output in the consumption (%)

113
112.9

109.5
134.8

128.8
138.3

151.2
112.0

(2) Increase the efficiency of recycling and reusing of zinc wastes
(scrap and waste products):
• Enhance the consciousnesses of resource depletion and the resource protection in individual’s and producer’s mind.
• Make complete laws and rules to regulate the recycling of zinc. • Perfect policy of tax and rules to encourage the activities on the resource recycling.
(3) Research and develop novel technology on recycling of zinc from secondary resources.
5. Conclusion
According to the substance flow analysis of zinc in 2006, in
China, it can be seen that:
(1) In the production and manufacture and fabrication stage, the self-supply efficiencies of zinc raw materials are 87.58% and
94.92%, respectively. For the total level, China has richer zinc raw resources. But, obviously, the self-supply efficiency in 2006 is lower than the average one. That means, the ratio of imported zinc ores in raw materials is increasing.
(2) In the production and manufacture and fabrication stage, the ratios of scrap to raw materials are 3.68% and 9.06%, respectively. Obviously, the recovery of zinc scraps is unsatisfactory; what is more, such index shows a downward trend.
(3) In the production stage, the indexes of zinc ore and zinc scrap are 1.1711 t/t and 0.0380 t/t, respectively. Impacted by rectification of mining industry, the index of zinc ores turn out lowest one in 2001. What is more, because of the lower utilization lever of zinc scrap resources all the time, with the production of zinc increasing, the index of zinc scrap decreased year by year.
Since most zinc flow into use as galvanized zinc, the separation and recovery of zinc scraps is difficult, so, most zinc have not flowed into eco-system through recycling and reuse. Furthermore, the low recovery efficiency, high cost, little profit, large pollution and lack of recognition and corresponding support policy have resulted in little specialize firm of secondary zinc and small production scale in China. By all appearance, so low recovery efficiency of secondary zinc attributes to all the reasons above.
Compared with other countries in the world, China has rich zinc resources, large productivity, and the output and consumption of zinc in the first place. However, lack of resources, prices of lead increasing and over-exploitation of zinc ores have resulted in short of zinc resources in China. The global production and consumption of zinc have greatly increased in recent years, the rapid develop-

167.6
96.9

231.8
87.5

255.1
93.7

292.6
87.08

311.53
91.30

14.06

ment of zinc production leads China to get in the first position of the world in the international zinc market. Along the increase of zinc production, the structure of industry and products, the products quality, the comprehensive utilization of resources, and the environmental protection, should be comprehensively improved simultaneously. References
Cohen D. Earth audit. New Scientist 2007;194(2605):8.
Daigo I, Hashimoto S, Matsuno Y, Adachi Y. Material stocks and flows accounting for copper and copper-based alloys in Japan. Resources, Conservation and Recycling
2009;53:208–17.
Di W. The import & export statistics of non-ferrous products in 2001. Non-ferrous
Metals Industry 2002;2:72–3.
Hansen E, Lassen C. Experience with the use of Substance Flow Analysis in Demark.
Applications and Implementation 2003;6(3–4):201–19.
Guo XY, Song Y. Substance flow analysis of copper in China. Resources, Conservation and Recycling 2008;52(6):874–82.
Guo XY, Tian QH. The resource recycling of nonferrous metal fundamental and approach. Changsha, Hunan: Central South University Publication; 2008.
Gordon RB, Graedel TE. The characterization of technological zinc cycles. Resources,
Conservation and Recycling 2003;39:107–35.
Gui H. The analysis of lead–zinc industry. Nonferrous Metals Industry 1999;7:
7–9.
Harper EM, Bertram M. The contemporary Latin America and the Caribbean zinc cycle: one year stocks and flows. Resources, Conservation and Recycling
2003;47:82–100.
Jiang JM. The status and sustained development of lead–zinc Smelting in China.
Journal of Chinese Non-ferrous Metals 2004;14(1):52–62.
Luo JS. The importance of renewable lead–zinc and the development of recycling economy. Hunan Nonferrous Metals 2005;21(6):18–20.
Liang K. The summary on the zinc metallurgical process. Nonferrous Metal Design
2004;31(4):13–7.
Lei J. Value of import decreasing, while imported raw materials increasing—brief comments of basic non-ferrous metal in 2001. Journal of Chinese Metals
2002;9:10–4.
Lei J. Active abroad, import & export increasing—foreign trade review of basic nonferrous metal in 2002. Journal of Chinese Metals 2003a;9:6–13.
Lei J. Active abroad, import & export increasing—foreign trade review of basic nonferrous metal in 2002. Journal of Chinese Metals 2003b;9:2–5.
Ma YG. Largest producer = power production. Renewable Resources Research
/
2002;2:12–4.
Peng RQ. Double import & export trade value of China’ non-ferrous metals three years later when entering WTO. China’ Molybdenum Industry
2005a;29(1):54–5.
Peng RQ. The import & export of non-ferrous metal trade surging record high. China’
Molybdenum Industry 2005b;30(2):49.
Qiu DF, Yiqian W. China’s recycling and use of non-ferrous metal resources (continued). Nonferrous Metallurgy Energy 2005;5(6):6–10.
Spatari S, Bertram M. The contemporary European zinc cycle: 1-year stocks and flows. Resources, Conservation and Recycling 2003;39:137–60.
Shang HL, Ruan HF. The current situation and forecasts of renewable industry in
China. Non-ferrous Metals Recycling and Utilization 2006;5:24–5.
Shi LL. Review of zinc situation in 2003. World Non-ferrous Metal 2004;5:32–3.
The Editorial Committee of Non-ferrous Metals Industry Yearbook of China. Nonferrous Metals Industry Yearbook of China. Beijing: Printing Company; 2007.
The Non-ferrous Metal Statistics. Non- Ferrous Metal Research Institute of Technical and Economic. Beijing: Printing Company; 2003–2007.

X. Guo et al. / Resources, Conservation and Recycling 54 (2010) 171–177
Wang W. Deficit of non-ferrous metal trade increasing by year—the large import of copper & aluminum is the main reason. International Economic Daily 2004.
Wu TJ, Wu YM. Trade situation of China’ main non-ferrous products in 2004. Journal of Chinese Metals 2005;17:7–12.
Wu YM. Analysis and prospect of non-ferrous product trade. World Non-ferrous
Metal 2007;4:70–1.

177

Zhou GB. Thinking on the development of lead–zinc industries. Nonferrous Metals
Industry 2003;9:11–3.
Zhao WZ. The import & export status of main non-ferrous metal products in China,
2000. Journal of Chinese Metals 2001;4:7–11.
Zhang JH, Lu ZW. The renewable resources & recycling way of zinc and status of renewable zinc in China. Resources Science 2007;29(3):86–93.