著者

五十嵐 信

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.110, no.9, pp.679-688, 1994-08-25 (Released:2011-01-27)

参考文献数

5

---

Akabira Colliery has been opend since 1938. The mine has many minable coal seams and is recentry extracting six seams, of them. The seams incline steeply toward syncline axis which runs across the central part of the mine from south to north. The mine has continued to product annualy washing coal from 1Mt to 2Mt since 1960's on a condition that there were mining trouble and safty caused by many faults and a lot of methane gas flow.In 1986, a change of coal situation that a demand of domestic coal took a sudden turn for the decrease because on an amendment of coal policy in Japan made Akabira Colliery determine to improve the basic structure of mining and safty. As the result, the structure of ventilation and transportation was simplified and made more efficient. And mining inside the shaft saftypillar has become a necessity. Heavy mechanised mining system replaced manual one. Akabira Colliery has become a new mine and come to be able to continue production in spite of severe situiation of domestic coal. Since the shaft is apt to be influenced or possibly damaged by ground movements, the prediction of shaft behavior due to mining, the monitoring of shaft deformations, and the repair of shaft damage should be executed as precisely as possible.This report shows experience of a drastic remodeling of mining structure and safty one which was carried out at Akabira Colliery from 1986 to 1994.

著者

藤田 豊久 佐野 葉奈 武藤 一 柴山 敦 宮崎 敏夫 井上 千弘

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.117, no.1, pp.43-48, 2001-01-25

被引用文献数

1

---

Bactrerium inhabiting in Amarume crude oil of Yamagata prefecture was identified as <i>Pseudomonas mendocina</i>. In the first step, biodegradation experiments were conducted by using the bacteria of 0.510⁶ cells / ml and 300 ppm of chlorobenzene in aqueous solution under aeration and irradiation. After 6 hours, chlorobenzene was perfectly decomposed. Next, the mixtures of synthesized polychlorinated dibenzo-<i>p</i>-dioxins (PCDDs) and dibenzofurans (PCDFs) were degraded with the bacteria of 0.510⁸ cells / ml, where the initial total concentrations of PCDDs and PCDFs were 1,400 ppm and 180 μg-TEQ / ml. After 24 hours, about 70 % of PCDDs and 60 % of PCDFs were biodegraded. The biodegradation rates of PCDD / Fs were much faster than those reported in literatures with other bacteria.<br>

著者

吉田 哲也 五十嵐 敏文 朝倉 國臣 宮前 博子 彌富 信義 橋本 晃一

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.120, no.10,11, pp.577-583, 2004 (Released:2006-05-09)

参考文献数

22

被引用文献数

1 3

---

To reduce the volume of precipitates generated by the neutralization of acid mine drainage (AMD) containing high concentrations of Fe and As, ferritization of the precipitates was attempted by a two-step neutralization process in which magnesium oxide (MgO) was used as the first neutralizer and sodium hydroxide (NaOH) as the second. Batch neutralization experiments with MgO and continuous flow experiments by the two-step neutralization were conducted in laboratories and an AMD treatment plant. The results showed that the precipitates by the neutralization were magnetized in the continuous flow experiments, although there was Al and Si that prevented the generation of ferrite in the AMD. This indicates that ferrite was formed from the precipitates after removing most of the soluble Al and Si by the first neutralization. In addition, aging of the precipitates under reducing conditions and returning the aged precipitates to a ferrite tank were required to form ferrite. The molar ratio of As to Fe in the precipitates reached a constant value at pH>3.5. This suggests the coprecipitation of As and Fe.

著者

井上 誠 岩井 正雄 鎌土 重晴 小島 陽 井藤 忠男 菅間 光雄

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.115, no.3, pp.189-194, 1999-03-25

参考文献数

12

被引用文献数

1 2

---

A newly recycling process for video camera components of AZ 91 D magnesium alloy used for professional market was developed by melting and casting processes in order to satisfy the JIS specifications for recycled AZ 91 D magnesium alloy ingot. Various quantities of Mn were added to the melt in order to avoid contamination by impurities such as Fe, Ni and Cr from paints. Composition analysis and mechanical properties and corrosion resistance of the recycled ingots were also examined. Recovery ratio of the recycled ingots is in the range of 60 % to 75 %. Chemical composition and tensile properties of the recycled ingot with Mn addition of more than 0.23 % is satisfied by JIS specification except for Cu content. Tensile strength and 0.2 % proof stress of the recycled ingots increase with increasing Mn content. The recycled specimens with Mn addition of more than 0.23 % almost exhibit the same level of corrosion resistance as the virgin ingot of AZ 91 D magnesium alloy.

著者

国吉 実 村上 次雄 溝田 忠人

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.118, no.7, pp.511-516, 2002-07-25

被引用文献数

2

---

Sodium bicarbonate easily forms cakes during the storage and / or transport process after production, due to the influence of conditions such as humidity, temperature, compaction etc. Caking causes serious degradation of the material in the commercial value. To overcome the problem, the caking mechanism must be clarified first, and thereafter the effective treatment should be considered to avoid caking. Weak caking strength of sodium bicarbonate powder at the initial stage of caking was measured and evaluated in relation to amounts of various components and physical properties of the powder. Caking under the high humidity (RH80%) of sodium bicarbonate found to occur due to the bridging among particles during the process of changing of sodium carbonate to sodium sesquicarbonate. The caking under the conditions of low humidity (RH40%) and high temperature (40 ∼ 50 °C) however owes bridging accompanied by the change from sodium carbonate to Wegscheider's salt. Caking strengths measured for sodium bicarbonate samples with various particle sizes were correlated with contacting numbers among particles. The caking strength, <i>B_L</i>, was found to be expressed with the equation: <i>B_L</i> = <i>k</i>·<i>Sc</i>·<i>F</i>, where <i>Sc</i> is the contact area per unit surface area of sodium bicarbonate particles, and <i>F</i> is the formation quantity per the unit surface area, of the double salts such as sodium sesquicarbonate and Wegscheider's salt. We have found finally an effective method to avoid caking through the process of analyzing the caking mechanism of sodium bicarbonate.

著者

朴 洗憲 山崎 哲生 島田 荘平 山本 恭久

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.118, no.10, pp.641-649, 2002-11-25

参考文献数

48

被引用文献数

3 3

---

Cobalt-rich manganese crusts on seamounts and manganese nodules on deep ocean floor have both been received attention as future resources for Co, Ni, Cu, and Mn. Lack of information on cobalt-rich manganese crusts has precluded comparisons between the two sources in terms of their technical and economical advantages. In the past 15 years, Japan has surveyed the cobalt-rich manganese crusts; therefore, it seems the proper time to compare the two. In this paper, we consider distribution features and R&D results to develop a method for examining and comparing the economical potentials of manganese nodule and cobalt-rich manganese crust mining. Through the preliminary evaluation of the two, the effectiveness of the method is confirmed. <BR>Cobalt-rich manganese crust development seems a risky but high return venture because of its high sensitivity to cobalt prices. Manganese nodule development, on the other hand, is considered to be a stable and good for a long-term venture. One of the application fields will be the selection of suitable metallurgical processing. A lower substrate ratio in excavated ore is clearly required for the economy of the crust development. In order to improve the evaluation, detailed technical information for the recovery efficiencies in the subsystems and units is necessary.

著者

大塚 尚寛 関本 善則

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.109, no.11, pp.897-902, 1993-11-25 (Released:2011-01-27)

参考文献数

8

---

It is considered that land deformation caused by open-cut mining influences on wind system around the quarry. Two case studies were conducted to investigate the change of wind system around the quarry.The results are summarized as follows:(1) Land deformations caused by open-cut mining were simulated with three dimensional computer graphics, and it became possible to forecast the changes of wind direction visually.(2) By use of quantitative formula that showed the relationship between lay of land and wind direction frequency, it became possible to forecast the changes of prevailing wind direction and wind direction frequency quantitatively.(3) It became clear that deforestation according to open-cut mining influenced on increase of wind speed around the quarry.(4) In case A, the ridge of the quarry will be mined, it was forecasted that change of wind system affected on living environment a little.(5) In case B, all over the mountain will be mined-out, it was forecasted that wind system around the quarry was changed widely.

著者

中野 正則

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.115, no.7, pp.498-504, 1999-07-25

---

IBUKI Limestone Quarry started operation from 1952. In order to obtain limestone ore resources, the exploitation plot plan for the upper lever was first considered in early 1970's. This area is adjacent to the natural park and natural monument area where high mountain plants are growing in groups. Prior to making the plot plan, the exploitation concept was discussed with experts and local communities and determined with regard to the natural environment. According to this concept, the excavating system including restoration on the planting and transporting system of limestone ore were developed. In order to verify restoration by planting and also to confirm the coexistence with mining work, the planting work had been performed since 1971 at the already excavated area below 1,000 meter level. On the other hand, the facilities for ore transportation were installed underground so that it cannot affect the existing landscape. Although rock had enough strength, strength of rock mass was not high due to considerable cracks observed. When the vertical ore shaft was constructed in the cracked rock, the diameter of the shaft was designed as a small scale and the walls were reinforced with concrete and steel ringing. To avoid choking in the shaft, the rock size supplied to the shaft is made under 300 mm using a mobile crushing plant. The operations in the upper limestone quarry was started in 1978, then the restoration planting at the upper limestone quarry was started in 1979. At the beginning of operation, there are many unexpected troubles in operations. This paper describes a design of exploitation which agreed with the concept, countermeasure for the troubles in operations, additional construction work to improve the environment against dust emission and the restored results in the excavated area.

著者

武田 邦彦 橋本 淳 棚橋 満

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.120, no.3, pp.139-145, 2004 (Released:2006-04-15)

参考文献数

52

---

Resource saving is thought to be one of the concepts and the acts necessary for environmental preservation. However, resource saving and its effect were examined and discussed from historical, regional, value and ethical viewpoints. From a historical viewpoint, the conversion from a society that used mainly sustainable resources to a society that uses non-sustainable resources was considered. From a regional viewpoint, Japan as a special region where there are little non-sustainable resources and a lot of consumption was taken up, and the influence of monopoly of worldwide resources by Europe and the United States was considered. In addition, in terms of value, the size of the overall gain of the acquisition of resources between generations was considered, and from an ethical viewpoint, the North-South problem was mainly analyzed. Also, regarding the conversion between resources, as the first approximation, the possibility of converting a general material into energy such as oil was shown, and the examination was advanced based on this. And then, it was pointed out that resource had not been saved in terms of the construction of a sustainable society even in the Edo period when resource had generally been maintained.

著者

作田 庸一 嶋影 和宜

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.120, no.2, pp.71-77, 2004-02-25

被引用文献数

1 2

---

A large amount of marine organic residue is generated and wasted from scallop shell processing manufacture. Because the waste product of scallop, especially the mid-gut gland contains a large quantity of heavy metals such as cadmium and copper, it cannot be effectively used. Now, a large part of these wastes are treated in landfills. However, in recent, the landfill treatment runs into trouble because of an environmental pollution and a decrease in proposed landfill ground. Consequently, the development of a new treatment method of the scallop waste is really required. In order to recycle the organic residue of scallop mid-gut gland, a new technology has been developed for removing the harmful cadmium and using as fish meal and fertilizer.<BR>This treatment consists of a cadmium leaching process from the mid-gut gland in a sulfuric acid solution and a cadmium electro-deposition process. This new treatment technology corresponding to hydrometallurgical process can remove more than 95% of cadmium from the mid-gut gland. At first, influences of various factors on cadmium removal efficiency such as acid concentration, electrolytic voltage, anode materials and so on, were examined to decide the most suitable conditions of an electrochemical treatment method by using a small scale plant test.<BR>And secondarily, a demonstration plant to enable one batch treatment of about 100kg/day was designed on the basis of the results of a fundamental experiment, and a prototype plant was built. Finally, a demonstration test was conducted.<BR>The dried and crushed wastes products of scallop after the removal of cadmium were reused as a feed and fertilizer materials, and in the year 2000, two recycle plants of the scallop waste on the basis of this development research were constructed at Oshamanbe-cho and Sawara-cho in Hokkaido, and now under operating.

著者

笹木 圭子 小林 弘幸 恒川 昌美

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.117, no.9, pp.747-752, 2001-09-25

被引用文献数

4

---

Aragonite-type of light calcium carbonate was synthesized by the successive reaction using calcined-hydrous scallop shells and calcined lime stones in the aqueous system with Mg²⁺ ions under the CO₂ bubbling. In order to obtain the high aspect ratios of aragonite, the reaction temperature and concentrations of Ca²⁺ ions in the 2nd step were important. The aspect ratio of aragonite increased when the reaction temperature was higher in the 2nd step than in the 1st step of the successive reaction. When the smaller amounts of calcium source were added in the 2nd step than in the 1st step, and the reaction temperature was lower in the 2nd step than in the 1st step, large particles of aragonite were produced with no smooth surfaces. The successive reaction was useful to extend the variety of morphologies in aragonite.

著者

笹木 圭子 本郷 大 恒川 昌美

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.114, no.10, pp.709-713, 1998-09-25

---

Aragonite-type calcium carbonate was synthesized from calcined scallop shell using carbonates of orthorohombic structure (such as SrCO3) as seeds, by bubbling CO2 at ambient temperature. The products were examined by FTIR, SEM, EPMA, and XRD. The addition of SrCO3 increased aragonite content in the products, but BaCO3 and PbCO3 did not play the role of seed crystals due to the difference of their lattice parameters to those of aragonite, whereas lattice parameters of SrCO3 are the most similar to them. With increasing SrCO3 -addition, formation of aragonite was accelerated to a limit in the amount. Light calcium carbonate rich in aragonite was formed in agglegates consisting of needle-like crystals with large specific surface areas.

著者

菅井 裕一 佐々木 久郎 松葉谷 治 中 秀男 田中 富士夫

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.121, no.10,11, pp.513-520, 2005 (Released:2007-02-24)

参考文献数

13

被引用文献数

4 6

---

The green tuff from Hinai town, Akita is popular for architectural materials because of its beautiful pale green color and thermal and moisture retaining properties. When this stone is quarried and grinded for making products, approximately 60% of all quarried stone becomes the waste stone and it is required to be utilized effectively. Hinai-Green tuff is a porous media and it has abilities to neutralize acids and elute some minerals. These abilities may be effective for growth of microbes and our research group carries out the development of effective utilizations of Hinai-Green tuff as microbial activator. In this paper, the effects of Hinai-Green tuff on pH adjustment and microbial activities are described.Hinai-Green tuff had an ability to neutralize both acid and alkaline water and especially neutralized acids effectivelly. For example, acid water of initial pH3 was neutralized to pH7 by adding 10(w/v)% Hinai-Green tuff into the acid water. Therefore, Hinai-Green tuff can neutralize acid soil and water and adjust acid environments to adaptable environments for microbes. Moreover, Hinai-Green tuff could buffer decrease in pH. The pH of water containing Hinai-Green tuff did not decrease rapidly with adding drops of 0.1M HCl, and especially the buffer action was strongly observed at pH 7 to 8. Hinai-Green tuff is very helpful to maintain pH appropriate for microbes for long time against decrease in pH caused by acid rain and/or acid metabolites of microbes. And pH adjustment effects of Hinai-Green tuff were caused by the ion exchange between Ca2+ leached from the stone and H+.Consequently, microbes grew actively in a medium containing Hinai-Green tuff because of its pH adjustment effects. However, microbes did not grow in a medium containing natural zeolite from Futatsui town, Akita. The effects of Futatsui-Zeolite on pH adjustment for acid were low compared with Hinai-Green tuff.

著者

西須 佳宏 小林 幹男 竹内 理

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.119, no.9, pp.573-578, 2003-09-25

---

The effect of regents concentrations for recovery and shape of precipitate on the liquid-phase synthesis of precursor particles of Y₂O₃ : Eu phosphor was studied. The amount of precipitant generated by hydrolysis of urea was remarkably changed by reaction temperature and initial concentration of urea. Therefore, the reaction rate of the precipitation reaction was controlled by reaction temperature and initial urea concentration. The recovery of precipitate was increased from < 10% to > 99% with the increase in urea concentration from 10 × 10^-3 to 30 × 10^-2 mol/dm³ in the synthesis at 92°C for 1 hour, when initial concentration of rare-earth ion was 10 mmol/dm³. On the other hand, the particle size was decreased with increase in urea concentration. The shape of particles was changed from uniform sphere to irregular aggregate with increase in initial concentration of rare-earth ion under the lower urea concentration condition. However, mono-dispersed spherical particles were formed even in that case, when the ratio of rare earth for the urea was higher. Though non-aggregated particles were amorphous basic carbonate; (Y, Eu)OHCO₃, the carbonate was crystallized in the aggregated particles. By the calcination at above about 600°C, both compositions converted to the oxide; (Y, Eu)₂O₃, but original shapes of precipitate particles were retained after that. Therefore, mono-dispersed spherical Y₂O₃ : Eu phosphor particles could be obtained from morphologically identical precursors. These results indicate the range of initial reagents concentrations in which mono-dispersed spherical Y₂O₃ : Eu phosphor is prepared.

著者

張 其武 齋藤 文良

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.114, no.4, pp.253-257, 1998-04-25

被引用文献数

11 30

---

Leaching of fluorescent powder containing rare earths using 1N HCl solution at room temperature was conducted to extract the rare earths, followed by dry grinding of the powder using a planetary ball mill. The dry mechanochemical treatment of the powder causes the structural change of the crystals in the powder into a disordered system. This mechanochemical treatment leads to easy extraction of the rare earths. Only 3 minutes of grinding enables us to extract Y and Eu at above 70-80 % yield. More than 80 % of the other rare earths can be extracted from the powder ground for 2-hours. The mechanochemical treatment to the fluorescent powder before leaching would be an effective operation to be able to extract the rare earths at high yield in room temperature leaching even by low concentration HCl solution.

著者

平島 剛 保坂 文教 本多 覚 恒川 昌美 伊藤 正澄 佐川 孝広

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.119, no.9, pp.553-558, 2003-09-25

被引用文献数

2 2

---

Fine waste concrete smaller than 5mm obtained from a recycling plant of waste concrete was used as feed and ground by a wet attrition mill. Recovery of the fine aggregate and cement hydrate powder from the ground fine waste concrete was investigated using a laboratory / pilot scale Mozley multi-gravity separator (MGS). The water absorption of the fine aggregate obtained as the high specific gravity product was less than 3.5 % and the dry density was larger than 2.4 g/cm³. The powder obtained as low specific gravity product contained about 29 % of fine aggregate. The reference for normal clinker and the mixture prepared by mixing the reference materials with 38 wt% of the powder were heated at 1,500 °C, with the hydraulic modulus adjusted to 2.18, the silica modulus to 2.8, and the iron modulus to 1.64. The phases of the clinker were identified and quantitatively determined by a microscopic point-count procedure and by the Rietveld analysis using XRD data. There was good agreement in the clinker minerals of the reference and the mixture clinkers. These results show that the fine aggregate and cement hydrate powder recovered from fine waste concrete by MGS can be recycled in cement and concrete production.

著者

三輪 加寿則

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.117, no.6, pp.527-532, 2001 (Released:2006-01-08)

---

Taiheiyo Cement's Garo Quarry, located in Kamiiso Town just west of Hakodate City in Hakkaido, is a historic quarry opened in 1892 to supply limestone for cement. There are no houses in the surrounding area. The closest residence is more than four kilometers away, and quarrying is carried out on a comparatively large scale under these blessed conditions. Within this enviironment, quarrying operations, carried out using the world's largest-class wheel loader and other large-scale heavy equipment, rank domestically among the top class in production efficiency. Further, careful consideration is given to protecting the surrounding environment and measures are taken to preserve the scenic view from Hakodate, a sightseeing area, and to prevent the generation of pollution from quarrying operations.As the magnesium oxide (MgO) content varies widely in the limestone deposits distributed throughout the quarry and there are frequent intrusions of clay, quality control is extremely difficult. Given these conditions, a quality control system has been introduced and operations are carried our under very strict quality control.In this paper, we will introduce the situation of open-pit quarrying operations at Garo Quarry.

著者

作田 庸一 嶋影 和宜

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.120, no.2, pp.71-77, 2004 (Released:2006-04-13)

参考文献数

32

被引用文献数

2

---

A large amount of marine organic residue is generated and wasted from scallop shell processing manufacture. Because the waste product of scallop, especially the mid-gut gland contains a large quantity of heavy metals such as cadmium and copper, it cannot be effectively used. Now, a large part of these wastes are treated in landfills. However, in recent, the landfill treatment runs into trouble because of an environmental pollution and a decrease in proposed landfill ground. Consequently, the development of a new treatment method of the scallop waste is really required. In order to recycle the organic residue of scallop mid-gut gland, a new technology has been developed for removing the harmful cadmium and using as fish meal and fertilizer.This treatment consists of a cadmium leaching process from the mid-gut gland in a sulfuric acid solution and a cadmium electro-deposition process. This new treatment technology corresponding to hydrometallurgical process can remove more than 95% of cadmium from the mid-gut gland. At first, influences of various factors on cadmium removal efficiency such as acid concentration, electrolytic voltage, anode materials and so on, were examined to decide the most suitable conditions of an electrochemical treatment method by using a small scale plant test.And secondarily, a demonstration plant to enable one batch treatment of about 100kg/day was designed on the basis of the results of a fundamental experiment, and a prototype plant was built. Finally, a demonstration test was conducted.The dried and crushed wastes products of scallop after the removal of cadmium were reused as a feed and fertilizer materials, and in the year 2000, two recycle plants of the scallop waste on the basis of this development research were constructed at Oshamanbe-cho and Sawara-cho in Hokkaido, and now under operating.

著者

笹木 圭子 本郷 大 恒川 昌美

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.114, no.10, pp.709-713, 1998-08-25 (Released:1999-10-01)

---

Aragonite-type calcium carbonate was synthesized from calcined scallop shell using carbonates of orthorohombic structure (such as SrCO3) as seeds, by bubbling CO2 at ambient temperature. The products were examined by FTIR, SEM, EPMA, and XRD. The addition of SrCO3 increased aragonite content in the products, but BaCO3 and PbCO3 did not play the role of seed crystals due to the difference of their lattice parameters to those of aragonite, whereas lattice parameters of SrCO3 are the most similar to them. With increasing SrCO3 -addition, formation of aragonite was accelerated to a limit in the amount. Light calcium carbonate rich in aragonite was formed in agglegates consisting of needle-like crystals with large specific surface areas.

著者

眞保 良吉 渡辺 薫生 鈴木 眞夫 星野 重夫

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.121, no.10,11, pp.538-543, 2005 (Released:2007-02-24)

参考文献数

5

---

As a certain method for decomposing harmful asbestos, it is proposed to dissolve the asbestos in molten slag of the pyrometallurgical smelting furnaces. Several dissolution tests have been achieved so far, and it has been suggested that the crystalline structures of the asbestos were decomposed before dissolving into slag. In this study, asbestos samples composed of chrysotile or crocidolite were heated in temperature range 800-1000°C, and the times required to decompose the crystalline structures of the asbestos were examined using X-ray diffraction analysis. Temperature higher than 900°C was required to wipe off the peaks of crocidolite, though chrysotile could be decomposed at 700°C. For both samples containing chrysotile and crocidolite, the peaks of asbestos in the X-ray diffraction patterns disappeared almost within 90 seconds when heated at 1000°C. However, the needle shapes were still maintained in both samples when they were simply heated at 1000°C.