New Clean Process for Barium Sulfide Preparation by Barite

Article pubs.acs.org/IECR

New Clean Process for Barium Sulfide Preparation by Barite Reduction with Elemental Sulfur Wei Zhang, Yong Zhou, Jiahua Zhu,* and Yanlin Pan School of Chemical Engineering, Sichuan University, Chengdu, 610065 Sichuan, PR China ABSTRACT: In order to reduce the emission of CO2, a thermodynamic and experimental investigation has been carried out to develop a new process for converting barium sulfate to barium sulfide involving elemental sulfur. In this improved process, the starting raw material barium sulfate was reduced by elemental sulfur to produce barium sulfide. The results indicated that the main products of BaSO4−S reaction produces were solid barium sulfide and sulfur dioxide, which could be used for producing sulfuric acid. Thermodynamic analyses showed that the reaction of the barium sulfate decomposition by sulfur was a complicated gas−solid reaction process with rising temperature. By simulation, the barium sulfate decomposition began at about 675 K and was completed at 1800 K. The thermodynamic and experimental results indicated that the rising reaction temperature and the increasing sulfur partial pressure contributed to reaction process. The decomposition temperatures of barium sulfate obtained by experiments were in a reasonable consistency with the simulation results, although they were a little higher than that obtained by simulation, due to the limited reaction time.

1. INTRODUCTION Barium sulfide is the most important and widely used barium compound, after natural barium sulfate (Barite). It is used in the lithopone, luminous paint, vulcanizing agent of the rubber and leather depilation agent. Moreover barium sulfide can be used in the manufacturing of other barium salts by treatment with suitable acids.1 The current industrial production of barium sulfide is based on a process called the black ash method, in which the raw Barite is reduced by coal in a rotary kiln at about 1100 °C. The black ash method may be presented as1−3

BaSO4 (s) + 4H 2(g) = BaS(s) + 4H 2O(g)

It was proposed as part of the cyclic reactions for reducing BaSO4 back to BaS which was reused as a reducing agent for converting sulfur dioxide gas to elemental sulfur.7 The advantage of this reducing scheme is that the gaseous product is only water vapor, which is beneficial for solving the environmental problems involved in desulfurization units for some industrial sectors.8,9 However, it may not be helpful concerning the energy savings and emission reduction in the production of barium sulfide from Barite, since using hydrogen as a reductant to replace carbon may spend more energy thus emitting more CO2, as comparing reaction 4 with reaction 1. China has been the world’s largest Barite-producing country since the 1980s and has widely distributed Barite deposits.10−12 Meanwhile, natural sulfur deposit is also huge in China.13−15 Based on the principle of coupling utilization of resources, a novel scheme of elemental sulfur reduction of Barite for coproduction of barium sulfide and sulfuric acid was proposed by the current authors. The essential reaction, as discussed in detail in the following sections, can be expressed as

BaSO4 (s) + 2C(s) = BaS(s) + 2CO2 (g), ΔHrx° = 208.388 kJ/mol

(1)

While the chemical reactions actually taking place between the two solid reactants are very complex, it is generally accepted that the real reducing agent is CO (reaction 2) which is regenerated by CO2 (reaction 3). CO2 is generated as a consequence of the gaseous reduction (reaction 2).3,4 BaSO4 (s) + 4CO(g) = BaS(s) + 4CO2 (g)

(2)

C(s) + CO2 (g) = 2CO(g)

(3)

BaSO4 (s) + S2 (g) = BaS(s) + 2SO2 (g)

(5)

The only gaseous product SO2 is just the high quality source material for the process of environmentally friendly production of sulfuric acid, in which SO2 is to be obtained from the oxidation of sulfur in pure oxygen:16

However, the coal reduction process for barium sulfate decomposition is an energy consuming process, in which two molecules of carbon are spent to convert one molecule of barium sulfate, resulting in a great amount of CO2 emission. The purpose of greenhouse gas emission control is to urgently develop a cleaner scheme and better technology than the black ash method, especially in a country with a huge industrial capacity for Barite conversion like in China. Barite reduction can be performed by using different reducing agents, such as methane, natural gas, and carbon monoxide.5,6 However they are not cleaner than coal in terms of energy savings and emission reduction compared with the black ash method. Another interesting process is the hydrogen reduction of BaSO4 to BaS: © 2014 American Chemical Society

(4)

S(s) + O2 (g) = SO2 (g)

(6)

Here the proposed coproduction scheme makes twice use of sulfur: first the raw sulfur as the reductant for production of barium sulfide and then the byproduct dioxide sulfur as an Received: Revised: Accepted: Published: 5646

December March 18, March 20, March 20,

15, 2013 2014 2014 2014

dx.doi.org/10.1021/ie4042356 | Ind. Eng. Chem. Res. 2014, 53, 5646−5651

Industrial & Engineering Chemistry Research

Article

Table 1. Thermodynamic Properties of Pure Phases Used in the Calculation coefficients of Cpc a

b

species

state

enthalpy H (kJ/mol)

entropy S (J/(mol•K))

A

B

C

D

temp range (K)

BaSO4

s s l s g s s s s s l g g g g g g g g g g g g

−1458.999

132.097

−463.600 −296.813 −553.543

78.450 248.220 70.290

112.415 170.000 170.000 49.379 43.430 4.351 250.055 −140.619 7.835 968.639 −8691.858 22.008 34.671 53.630 78.089 75.001 130.546 129.235 153.294 157.958 166.175 181.066 208.668

51.558 0.000 0.000 6.672 10.627 −8.284 −240.645 97.291 79.793 −3355.340 28083.985 −0.418 3.286 6.274 6.938 70.637 −15.763 2.613 6.200 0.005 22.024 40.436 −12.249

−22.834 0.000 0.000 −1.796 −5.941 0.000 −381.183 1149.765 −0.207 −223.772 2467.293 1.506 −2.816 −7.572 −11.025 −4.544 −68.557 −15.098 −18.799 −25.626 −15.062 −95.826 59.283

−0.002 0.000 0.000 0.085 0.000 0.000 81.896 −0.067 −97.893 3368.169 −25321.119 0.000 −0.312 −2.324 −2.570 −34.582 2.596 1.754 −2.192 0.000 8.312 −18.249 1.543

298.15−1423 1423−1853 1853−4000 298.15−2500 298.15−1800 298.15−1600 1200−1600 1600−2246 100−368 368−388 388−428 298.15−2000 298.15−2000 298.15−1500 298.15−1500 298.15−900 900−2800 298.15−1900 298.15−1500 1500−6000 298.15−800 800−1500 1500−3700

BaS SO2 BaO

S S S S2 S3 S4 S5 S6 S7 S8

31.882

279.408 128.658 146.440 188.280 109.400

67.737 228.028 275.952 325.934 308.600

98.742 102.926

353.883 394.099

96.839

423.128

a c

Standard molar formation enthalpy, standard state is at T = 298.15 K. bStandard entropy of the substance, standard state is at T = 298.15 K. Coefficients of molar heat capacity under constant pressure.

2.2. Equilibrium Compositions of Sulfur Reacting with Barium Sulfate. The calculated equilibrium compositions for the reaction composed of 1 mol of barium sulfate and 2 mol of sulfur at a total pressure of 1 atm, as shown in Figure 1. The

alternative supply for production of sulfuric acid. From the point of view of energy savings and emission reduction, the coproduction scheme would be very promising to replace the black ash method for the production of barium sulfide from Barite. In this work, thermodynamic simulations and experiments were carried out to the system concerning the essential chemical reaction 5 under temperatures between 600 and 1800 K. The simulated equilibrium compositions were verified by the experiments.

2. THERMODYNAMIC ANALYSIS 2.1. Thermodynamic Methods. The net reaction equations of the barium sulfate decomposition by sulfur are as follows: nBaSO4 (s) + 2Sn (g) = nBaS(s) + 2nSO2 (g)

(7)

Those reactions are considered to occur by the following BaS(s) + 3BaSO4 = 4BaO(s) + 4SO2 (g)

(8)

mSn(g) = nSm(g), (m , n = 1−8; m ≠ n)

(9) Figure 1. Equilibrium composition against temperature for a mixture of 1 mol of BaSO4 and 2 of mol S at a total pressure of 1 atm.

where n and m in the reactions 7 and 9 represent multiple atoms. The equilibrium compositions of the above three reaction equations were simulated by HSC Chemistry software.17−21 The criterion for the simulation is minimization of Gibbs free energy with two hypotheses. The first hypothesis is that all of the input substances are considered as ideal substances, and two or multiple substances are assumed to be completely mixed when they are defined as the same phase. The second one is that the initial system would finally reach equilibrium.22 The thermodynamic data for the calculation of enthalpy changes of the reactions are listed in Table 1.18,23,24

amounts of all sulfur species were considered in reaction 7. The simulation results of sulfur species equilibrium compositions were in concordance with the reported results.25−27 It is generally considered that the gaseous sulfur is a mixture of different sulfur molecules with one to eight atoms at lower temperature (⩽1000 K),26,28 and the reaction of the barium sulfate decomposition by sulfur was a complicated gas−solid reaction process with rising temperature. At higher temperature (⩽1000 K), gaseous sulfur 5647



Article

detailed reaction process. An SK2 tube resistance stove (Tianjing Zhonghuan Experiment Stove Company, Ltd.) was used. 3.2. Experimental Materials. The raw materials in the experiments included sulfur, barium sulfate, and nitrogen gas, after drying 45 min at 413 K. Provenance and purity values of these raw materials are listed in Table 2.

with two atoms is the primary phase. Therefore, the decomposition of barium sulfate by sulfur is mainly determined by reaction 5. It is noted that the equilibrium conversion was measured and presented in terms of the conversion of solid barium sulfate. As shown in Figure 1, the equilibrium conversion increased monotonically with temperature. For example, the conversion is 46.18% at 1367 K and 94.28% at 1638 K. Furthermore, it is seen that the solid contains only barium sulfide and unreacted barium sulfate. The results are in concordance with the X-ray pattern of solid products. Therefore, the reaction process of sulfur reacting with barium sulfate is feasible without generating secondary pollutants. The effect of temperature on the reaction was simulated by varying the temperature between 600 and 1800 K, as shown in Figure 2. It is seen that the starting temperature of barium sulfate

Table 2. Provenance and Purity Values of Raw Materials raw materials sulfur barium sulfate nitrogen gas

provenance Kelong Limited Liability Company, Sichuan, China Kelong Limited Liability Company, Sichuan, China Dongfeng Industrial Gases Limited Company, Sichuan, China

mass fraction purity 0.9950 0.9800 0.9999

3.3. Experiments in a Tube Reactor. A method to control partial pressure of sulfur, PS2, was developed by Takashi Uchida et al.29 To provide a stable sulfur partial pressure and verify the reaction system, a tube reactor was used to analyze the decomposition process of barium sulfate, as shown in Figure 3.The experimental setup consisted of four major partsa N2 gas cylinder, a gasification furnace, a decomposition furnace, and an alkali liquor vessel. A total of 40 g of sulfur was placed in the gasification furnace, and 6.5 g of barium sulfate was placed in a little porcelain boat. The boat was placed in the middle of the decomposition furnace. When the temperature was increased to the reaction temperature of 800 to 1700 K, then sulfur was gasified at 623 to 723 K and introduced into the decomposition furnace by a nitrogen carrier gas with a flow rate of 400 cm3· min−1. The experiments were carried out for 1 h. Then, the reactant was cooled with nitrogen after the reaction and collected with a sample bag. Alkali liquor was used to absorb the sulfur dioxide of the tail gas produced in the reaction. In order to measure the actual partial pressure of sulfur at the reaction temperature, the sulfur sensor was used.

Figure 2. Effect of temperature on the reaction of BaSO4 with S by simulation at a total pressure of 1 atm.

4. EXPERIMENTAL RESULTS 4.1. Reaction Products. For the BaSO4−S reactions, a gas mixture containing nitrogen and sulfur at a partial pressure of 18.45 kPa was passed over the barium sulfate held in a porcelain boat for various reaction temperatures. Figure 4 shows the X-ray pattern of barium sulfate and solid products. The characteristic X-ray peaks of barium sulfate (JCPDS File No. 24-1035) are illustrated in Figure 4(a), Figure 4(b), and Figure 4(c) (20.4°, 22.8°, 24.1°, 25.9°, 28.8°, 31.6°, 32.8°, 40.8°, 42.9°, 52.9°, 54.8°, 60.2°); and the XRD peak of barium sulfide (JCPDS File No. 080454) is shown in Figure 4(b) and Figure 4(c) (24.1°, 27.9°, 39.9°, 47.2°, 49.4°, 57.6°, 63.4°, 65.2°, 72.3°). It is seen that the solid products contains only barium sulfide and unreacted barium sulfate. Barium oxide (JCPDS File No. 01-0746) (27.9°, 32.5°, 46.5°, 55.3°, 57.95°, 77.6°) could not be found in the production. The results are in good agreement with Figure 1. Comparing Figure 4(b) with Figure 4(c), it is noted that the relative peak intensity of barium sulfide increases with the temperature rising. Hence, a higher temperature favors the reaction. The relative intensity ratio (RIR) method is one of the simplest and quickest ways to quantify X-ray diffraction data.30,31 In this experiment, the relative intensity ratio (RIR) method was used to conduct quantitative XRD.

was about 675 K (the conversion is 0.1%) under a sulfur partial pressure of 35 kPa, and the equilibrium conversion increases steadily with temperature at lower temperature (≤1000 K). The equilibrium conversion substantially increases with the rise of temperature, when the temperature is greater than 1000 K, and it decomposed completely at 1800 K. To show the effect of sulfur partial pressure on the reaction, the reaction was simulated at a total pressure 1 atm from a starting mixture of 1 mol of barium sulfate, 2 mol of sulfur and N2, as shown in Figure 2. The equilibrium conversion increased with increasing sulfur partial pressure at the lower temperature. At higher temperature (≥1400 K), the effect of sulfur partial pressure decreased with increasing reaction temperature and was almost negligible at 1600 K.

3. EXPERIMENTAL WORK To verify the thermodynamic simulation of sulfur reduction barium sulfate, experiments were carried out in this study to investigate barium sulfate decomposition by sulfur since such sulfur reduction reactions involve gas−solid reactions and solid− solid reactions were designed. 3.1. Experiment Equipment. The solid products of the verified experiments were characterized by X-ray diffraction (Royal Philips Electronics NV, X’Pert Pro) so as to indicate a 5648



Article

Figure 3. Experimental setup for the verified experiment.

Figure 4. X-ray pattern of barium sulfate and solid products: (a) X-ray pattern of BaSO4; (b) X-ray pattern of solid products at T = 1400 K; (c) X-ray pattern of solid products at T = 1500 K; (d) the standard pattern for BaO (JCPDS File No. 01-0746).

⎛ I ⎞⎛ X ⎞ i ⎟ Xj = ⎜⎜ hkli ⎟⎟⎜⎜ ⎟ I RIR ⎝ hklj ⎠⎝ i,j ⎠

The general definition of the RIR for phase j to reference phase i is given by32 ⎛ I ⎞⎛ X j ⎞ RIR i , j = ⎜⎜ hkli ⎟⎟⎜ ⎟ ⎝ Ihklj ⎠⎝ Xi ⎠

(11)

The RIR value may be obtained by determination of the slope of the standard calibration plot or from other RIR values by

(10)

RIR i , j =

where Ihkl is the intensity, and X is the weight fraction. Rearranging the above equation 5649

RIR i , k RIR j , k

(12)



Article

Chung recognized that if a mixture is comprised of known phases each with known values of RIR, the fractions for the phases must add to 1.33,34 This allows the following summation equation to be written ⎡ ⎤ 1 ⎥ Xi = (IhkIi)(K i , n)⎢ m ⎢⎣ ∑ j = 1 (IhkI ,j)(Kj , n) ⎥⎦

(13)

in which Xi is the unknown weight fraction of phase i in the sample, Ki,n and Kj,n are the RIR for the strongest diffraction line of phase i and j, Ii,n and Ij,n are the integrated intensity of the strongest diffraction line of phase i and j, respectively, and m is the number of phases in the mixture. In these calculations, Al2O3 (JCPDS File No. 10-0173) was employed as a reference phase to determine if relative intensity factors were used. The reaction rate was measured and is presented in terms of the conversion of solid barium sulfate. The conversion may be obtained by calculating the unreacted barium sulfate weight fraction (the RIR method) in the solid products R=1−

X1M 2 M1

Figure 5. Plot of conversion rate of BaSO4 against temperature at pS2 = 18.5 kPa and pS2 = 8.6 kPa.

(14)

in which R is the percent conversion of solid barium sulfate. X1 is the unreacted barium sulfate weight fraction in the solid products, M1 is the mass of the raw barium sulfate reactants, and M2 is the mass of the solid products. The calculated reference intensity ratios (RIR) of solid products at T = 1400, 1500 K are shown in Table 3. According to the results of the parallel experiment, the standard deviation (SD) of this method was between 0.02 and 2.8%, and the data were presented as the mean ± SD.

explanation is due to the limited reaction time (1 h), while the reaction equilibrium was not reached. However, it is seen that the tendency of the experimental result is in a reasonable consistency with the simulation results in Figure 2.

5. CONCLUSIONS A new process of barium sulfate decomposition by sulfur is investigated by both thermodynamic simulation and experiments. The results demonstrate that elemental sulfur is applicable for converting barium sulfate to barium sulfide. Thermodynamic analyses showed the gaseous sulfur is a mixture of different sulfur molecules with one to eight atoms at lower temperature (⩽1000 K), and the barium sulfate decomposition by sulfur is a complicated gas−solid reaction process. Significant conversion was observed at 675 K, while complete conversion was obtained at 1800 K. The thermodynamic results indicate that the rising reaction temperature and the increasing sulfur partial pressure are a benefit for the decomposition reaction process. The decomposition temperatures of barium sulfate obtained by experiments are a little higher than that calculated by thermodynamic simulation, probably due to the limited reaction time, and the reaction equilibrium was not reached. The solid barium sulfate can be reduced to regenerate barium sulfide without generating any waste solids. The X-ray pattern of the final solid phase indicated that the solid contains only barium sulfide and unreacted barium sulfate. Barium oxide could not be found in the production. This is in agreement with the thermodynamic analyses. Obviously this reaction scheme is more attractive than the black ash process; the former one produces only SO2, while the latter one produces mostly CO2. The proposed coproduction scheme has the advantage of making full use of sulfur. First use sulfur as the reductant in the production of barium sulfate to convert into SO2. Then the only gaseous product of barium sulfide (SO2) can be used to produce sulfuric acid. Therefore from the point of energy savings and emission reduction in the production of barium sulfide from Barite, the coproduction scheme can be considered as a basis of the green chemistry for developing environmentally friendly future industries.

Table 3. Calculated Reference Intensity Ratios (RIR) of Solid Products at T = 1400, 1500 K temp (K)

chemical formula

RIR

conversion (%)

1400

BaS BaSO4 BaS BaSO4

11.12 2.60 11.12 2.60

61.04 ± 1.3

1500

92.55 ± 2

The results show that the conversion is 61.04 ± 1.3% at 1400 K; moreover, the conversion is 92.55 ± 2% at 1500 K. 4.2. Effect of Reaction Temperature. The effect of the reactions temperature was investigated by varying the temperature in the range 800−1700 K. As shown in Figure 5, the conversion curve has a sigmoidal shape. The experimental data presented indicate that barium sulfate started to decompose after 800 K. Meanwhile, the conversion increased as the temperature rises: the conversion grew steadily under 1200 K, raised relatively rapid till 1500 K when the sulfur partial pressure is 18.5 kpa (1600 K when the sulfur partial pressure is 8.6 kpa), and then grew steadily again. Furthermore, the increasing sulfur partial pressure improves the conversion and the mass transfer apparently according to the experimental data. At the temperature of 1700 K the conversion is 98.1 ± 1.2% under a sulfur partial pressure of 18.5 kPa, while the conversion is only 75.60 ± 2.1% under a sulfur partial pressure of 8.6 kPa at the same reaction temperature. By comparing the simulation results in Figure 2, the decomposition temperatures of barium sulfate are a little higher than the thermodynamic simulation results; a possible 5650



■

Article

(18) Barin, I.; Knacke, O.; Kubaschewski, O. Thermochemical properties of inorganic substances: supplement; Springer-Verlag: New York, 1977. (19) Pankratz, L. B. Thermodynamic properties of halides; US Department of the Interior, Bureau of Mines: WA, 1984. (20) Erikkson, G. Thermodynamic studies of high temperature equilibria. XII. SOLGASMIX, a computer program for calculation of equilibrium compositions in multiphase systems. Chem. Scr. 1975, 8, 100−103. (21) White, W. B.; Johnson, S. M.; Dantzig, G. B. Chemical equilibrium in complex mixtures. J. Chem. Phys.. 1958, 28, 751. (22) Roine, A. Outokumpu HSC chemistry for windows: chemical reaction and equilibrium software with extensive thermochemical database; Outokumpu: Pori, Finland, 2002. (23) Ye, D. Handbook of Thermodynamic Data for Applied Inorganic Material; Metallurgical Industry Press: Beijing, China, 1981. (24) Liang, Y.; Che, Y. Handbook of Thermodynamic Data for Inorganic Material; Northeaster University Press: Shenyang, China, 1993. (25) Yan, L. The calculation of equilibrium composition of sulfur vapor in Claus process. Comput. Appl. Chem. (China) 1990, 7 (1), 26−29. (26) Yang, X.; Zhang, Z.; Wang, X.; Yang, L.; Zhong, B.; Liu, J. Thermodynamic study of phosphogypsum decomposition by sulfur. J. Chem. Thermodyn. 2013, 57, 39−45. (27) Ferreira, A. G. M.; Lobo, L. Q. The low-pressure phase diagram of sulfur. J. Chem. Thermodyn. 2011, 43 (2), 95−104. (28) Yao, F.; Guo, D.; Gui, M. Oxygen, Sulfur and Selenium; Science Press: Beijing, China, 1990; Vol. 5. (29) Uchida, T.; Yoneyama, T.; Yoshida, M.; Wakihara, M.; Taniguchi, M. A new method to control partial pressure of sulfur in an oxygen free hydrogen-sulfur atmosphere. Mater. Res. Bull. 1990, 25 (10), 1263− 1270. (30) Hubbard, C. R.; Snyder, R. L. RIRmeasurement and use in quantitative XRD. Powder Diffr. 1988, 3 (2), 74−77. (31) Kahle, M.; Kleber, M.; Jahn, R. Review of XRD-based quantitative analyses of clay minerals in soils: the suitability of mineral intensity factors. Geoderma 2002, 109 (3), 191−205. (32) Al-Jaroudi, S. S.; Ul-Hamid, A.; Mohammed, A.-R. I.; Saner, S. Use of X-ray powder diffraction for quantitative analysis of carbonate rock reservoir samples. Powder Technol. 2007, 175 (3), 115−121. (33) Chung, F. H. Quantitative interpretation of X-ray diffraction patterns of mixtures. I. Matrix-flushing method for quantitative multicomponent analysis. J. Appl. Crystallogr. 1974, 7 (6), 519−525. (34) Chung, F. H. Quantitative interpretation of X-ray diffraction patterns of mixtures. II. Adiabatic principle of X-ray diffraction analysis of mixtures. J. Appl. Crystallogr. 1974, 7 (6), 526−531.

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS This work was supported by the National Key Technology R&D Program of China (Grant No. 2013BAC12B01). We would like to thank Doctor Jiabei Zhou for the helpful suggestion and correction for this work.

■

REFERENCES

(1) MacWilliams, D. C. Kirk-Othmer: Encyclopedia of Chemical Technology; Wiley: New York, 1978. (2) Lung, C.; Chen, S.; Wu, J. Study on the reducing conditions of the barite in Boyang. J. Nanchang Univ. 1991, 15 (1), 1−6. (3) Bafghi, M. S.; Yarahmadi, A.; Ahmadi, A.; Mehrjoo, H. Effect of the type of carbon material on the reduction kinetics of barium sulfate. Iran. J. Mater. Sci. Eng. 2011, 8, (3). (4) Jagtap, S. B.; Pande, A. R.; Gokarn, A. N. Effect of catalysts on the kinetics of reduction of Barite by carbon. Ind. Eng. Chem. Res. 1990, 29 (5), 795−799. (5) Shakhtakhtinskii, G.; Yusubov, R.; Samedova, A. Reduction of a granulated Barite concentrate by converted natural gas in a fluidized bed. Azerb. Khim. Zh. 1972, 4, 114−116. (6) Jamshidi, E.; Ebrahim, H. A new clean process for barium carbonate preparation by Barite reduction with methane. Chem. Eng. Process.: Process Intensif. 2008, 47 (9), 1567−1577. (7) Sohn, H. Y.; Savic, M.; Padilla, R.; Han, G. A novel reaction system involving BaS and for converting to elemental sulfur without generating pollutants: Part I. Feasibility and kinetics of reduction with BaS. Chem. Eng. Sci. 2006, 61 (15), 5082−5087. (8) Sohn, H. Y.; Savic, M.; Padilla, R.; Han, G. A novel reaction system involving BaS and for converting to elemental sulfur without generating pollutants: Part II. Kinetics of the hydrogen reduction of to BaS. Chem. Eng. Sci. 2006, 61 (15), 5088−5093. (9) Sohn, H. Y. Thermodynamics of a new cyclic reaction system involving BaS and BaSO4 for converting sulfur dioxide to elemental sulfur. Ind. Eng. Chem. Res. 2003, 42 (23), 5946−5948. (10) Sun, H.; Wu, J.; Yu, P.; Li, J. Geology, geochemistry and sulfur isotope composition of the Late Proterozoic Jingtieshan (Superior-type) hematite-jasper-Barite iron ore deposits associated with stratabound Cu mineralization in the Gansu Province, China. Miner. Deposita 1998, 34 (1), 102−112. (11) Clark, S. H. B.; Poole, F. G.; Wang, Z. Comparison of some sediment-hosted, stratiform Barite deposits in China, the United States, and India. Ore Geol. Rev. 2004, 24 (1−2), 85−101. (12) Yang, R.; Wei, H.; Bao, M.; Wang, W.; Wang, Q.; Zhang, X.; Liu, L. Discovery of hydrothermal venting community at the base of Cambrian Barite in Guizhou Province, Western China: Implication for the Cambrian biological explosion. Prog. Nat. Sci. 2008, 18 (1), 65−70. (13) Fu, J.; Sheng, G. A preliminary study of asphalt from a large sulphur deposit in China by the approach of molecular organic geochemistry. J. Pet. Sci. Eng. 1999, 22, 95−102. (14) Peng, H.; Guizhi, N. Discussion on China sulfur oreconcentrating area and the resource potential. Geol. Chem. Miner. (China) 2010, 32 (2), 95−104. (15) Zhang, X.; Baruch, S.; Chris, H. Sulphur sources of sulphides from the lannigou and getang sedimenthosted gold deposits, SW Guizhou, China. Chin. Sci. Bull. 1998, 43, 158−158. (16) Pan, T.; Liang, B.; Tan, Y. A new process for sulfuric acid preparation by sulfur with pure oxygen. Sulphuric Acid Ind. (China) 2010, 2, 32−32. (17) Eriksson, G.; Hack, K. ChemSagea computer program for the calculation of complex chemical equilibria. Metall. Trans. B 1990, 21 (6), 1013−1023. 5651


New Clean Process for Barium Sulfide Preparation by Barite

Recommend Documents