共查询到19条相似文献，搜索用时 140 毫秒
1.
采用雷蒙磨粉机对－３ｍｍ金标准参考样品加工至－３２５目，再经球磨机混匀，均匀度检验证明，未发现任何不均匀性。 相似文献
2.
3.
不同钵体研磨地质样品产生的元素污染及粒度分布探讨 总被引：3，自引：0，他引：3
采用玛瑙钵体碎样，随着研磨时间加长，样品粒度可以变得更细。但与碳化钨钵体相比，达到同样粒度所需研磨时间较长，且清洗困难，会造成样品之间的污染。用碳化钨钵体碎样，粒度在研磨4min后可达到70μm，但研磨5min和6min，粒度无明显变细。在两种钵体中，除碳化钨钵体对样品造成了严重的Co污染外，对所测定的其它微量元素，均未造成明显污染。 相似文献
4.
为使样品加工粒度200目的过筛率平均达到98％以上，满足X荧光分析对样品粒度的基本要求，在实验过程中发现了饭颗粒存在并影响着过筛率，通过分析饭颗粒的成因，找出了有效抑制饭颗粒的办法——加入酒精在一定的条件下能抑制饭颗粒的产生并能保证样品加工粒度达到200目过筛率平均在98％以上。 相似文献
5.
富钴结壳超细标准物质的加工制备 总被引：3，自引：2，他引：1
用气流磨制备了2个具有超细粒度的海山富钴结壳标准物质MCPt-1和MCPt-2。原样先经球磨成74μm(-200目),再用气流磨进行超细加工。样品粒度采用激光粒度仪检测,用粒度分布图和特征粒度来表达测量结果。两个样品的平均粒度分别为1.8μm和1.5μm(约2 000目),是目前粒度最小的标准物质。文章介绍了用于超细加工的流化床式气流磨原理与方法,展示了样品加工后的粒度分析结果,对比了国内外超细标准物质的概况。最后讨论了当前关注样品加工的重要性、超细加工的问题及超细样品分析研究的意义。 相似文献
6.
新疆哈密地区红山金矿区的样品中，有品位的样品大多含有明金．但含明金的样品又多为难加工的金矿样品，由此带来的测试结果不稳定等问题，严重影响了分析测试质量．笔认为中碎缩分粒度和细碎时间，是影响加工质量的重要因素，而中碎缩分粒度的确定又成为制定合理的样品加工流程的关键．笔采用重砂鉴定和样品加工流程试验相结合的方法，进行综合分析判断后，确定了红山金矿区样品中碎缩分粒度，从而制定了合理的加工流程，保证了加工完毕的样品有较好的代表性和均匀性，进一步保证了测试结果的准确性和重现性．该流程在2003年度红山矿区金矿样品加工中使用，样品双份分析的一次性合格率为98．0％，内检合格率达88．7％，外检合格率达96．8％。达到规范要求． 相似文献
7.
在洲量铜矿石含铜品位方面，用X荧光分析方法代替化学分析，其快速、方便、经济的特点已得到充分肯定。由于样品加工程序繁琐复杂，尝试采用放宽扮样粒度条件，减轻样品加工工作量。通过试验，选择-30目作为荧光分析的扮样粒度，能满足实际生产和技术的需要。 相似文献
8.
9.
提高金矿地质样品制样质量的途径 总被引：6，自引：0，他引：6
金矿地质样品制备过程中，粒度和质量是保证样品代表性的关键，在此基础上，把握好样品缩分，细碎工艺2个环节，即可获得较为理想的分析样品，提高金矿地质样品制样质量应增加样品采集次数，有效控制损失率，建立快速高效的质量反馈机制，从而进一步提高“采加化”工作质量。 相似文献
10.
11.
Mineral carbonation is one of several alternatives for CO2 sequestration and storage. The reaction rates of appropriate minerals with CO2, for instance olivine and serpentine with vast resources, are relatively slow in a CO2 sequestration context and the rates have to be increased to make mineral carbonation a good storage alternative. Increasing the dissolution rate of olivine has been the focus of this paper. Olivine was milled with very high energy intensity using a laboratory planetary mill to investigate the effect of mechanical activation on the Mg extraction potential of olivine in 0.01 M HCl solution at room temperature and pressure. Approximately 30–40% of each sample was dissolved and water samples were taken at the end of each experiment. The pH change was used to calculate time series of the Mg concentrations, which also were compared to the final Mg concentrations in the water samples. Percentage dissolved and the specific reaction rates were estimated from the Mg concentration time series. The measured particle size distributions could not explain the rate constants found, but the specific surface area gave a good trend versus dissolution for samples milled wet and the samples milled with a small addition of water. The samples milled dry had the lowest measured specific surface areas (<4 m2/g), but had the highest rate constants. The crystallinity calculated from X-ray diffractograms, was the material parameter with the best fit for the observed differences in the rate constants. Geochemical modelling of mechanically activated materials indicated that factors describing the changes in the material properties related to the activation must be included. The mechanically activated samples in general reacted faster than predicted by the theoretical models. Mechanical activation as a pre-treatment method was found to enhance the initial specific reaction rates by approximately three orders of magnitude for a sample milled dry for 60 min in a planetary mono mill compared to an unactivated sample. Wet milling in the planetary mill did not produce samples with the same maximum reaction rate as dry milling, but wet milling in general might be easier to implement into a wet carbonation process. Mechanical activation in a planetary mill is likely to consume too much energy for CO2 sequestration purposes, but the increase in obtained olivine rate constants illustrates a potential for using milling as a pre-treatment method. 相似文献
12.
The 234U/238U alpha activity ratio (AR) was determined in 47 samples of variably uraniferous groundwater from the vicinity of a uranium mill near Cañon City, Colorado. The results illustrate that uranium isotopes can be used to determine the distribution of uranium contamination in groundwater and to indicate processes such as mixing and chemical precipitation that affect uranium concentrations. Highly to moderately contaminated groundwater samples collected from the mill site and land immediately downgradient from the mill site contain more than 100?μg/l of dissolved uranium and typically have AR values in the narrow range of 1.0–1.06. Other samples from the shallow alluvial aquifer farther downgradient from the mill contain 10–100?μg/l uranium and plot along a broad trend of increasing AR (1.06–1.46) with decreasing uranium concentration. The results are consistent with mixing of liquid mill waste (AR≈1.0) with alluvial groundwater of small, but variable, uranium concentrations and AR of 1.3–1.5. In the alluvial aquifer, the spatial distribution of wells with AR values less than 1.3 is consistent with previous estimates of the probable distribution of contamination, based on water chemistry and hydrology. Wells more distant from the area of probable contamination have AR values that are consistently greater than 1.3 and are indicative of little or no contamination. The methodology of this study can be extended usefully to similar sites of uranium mining, milling, or processing provided that local geohydrologic settings promote uranium mobility and that introduced uranium contamination is isotopically distinct from that of local groundwater. 相似文献
13.
Xiaohong Wang Yimin Wang Yushu Gao Yongyang Huang Zhenyu Wang Xuefa Shi 《Geostandards and Geoanalytical Research》2009,33(3):357-368
We report the preparation and characterisation of five sediment reference materials MSCS-1–5 from the China Sea and continental shelf. The raw samples were individually collected from the East China Sea and the South China Sea. They were first ground by ball mill to a homogenous powder of -200 mesh (< 74 μm). Then, half of each sample was further processed by an ultra-fine powder processing technique, a jet mill, to form a powder with an average particle size of < 4 μm (about 800 mesh). The homogeneity was tested by high-precision WD-XRF and the precision was found to be less than 1% RSD, which is compatible with the precision range for modern analytical techniques. An F-test showed that all five samples were homogeneous. Twelve laboratories participated in the cooperative study and sixty constituents were determined. Between fifty and fifty-two analytes were characterised as recommended values in MSCS-1–5 in compliance with Chinese national norms. The sum of the major and minor elements or components in the five reference materials MSCS-1–5 was 99.91%, 99.86%, 100.43%, 100.12% and 99.66%, respectively. 相似文献
14.
《Applied Geochemistry》2006,21(2):269-288
Reliable quantification of mineral weathering rates is a key to assess many environmental problems. In this study, the authors address the applicability of pure mineral laboratory rate laws for dissolution of mill tailings samples. Mass-normalised sulfide and aluminosilicate mineral dissolution rates, determined in oxygenated batch experiments, were found to be different between two samples from the same ∼50-year-old, carbonate-depleted mill tailings deposit. Consideration of difference in particle surface area and mineralogy between the samples resolved most of this discrepancy in rates. While the mineral surface area normalised dissolution rates of pyrite in a freshly crushed pure pyrite specimen and a sulfide concentrate derived from the tailings were within the range of abiotic literature rates of oxidation by dissolved molecular O2, as were rates of sphalerite and chalcopyrite dissolution in the tailings, dissolution rates of pyrite and aluminosilicates in the tailings generally differed from literature values. This discrepancy, obtained using a consistent experimental method and scale, is suggested to be related to difficulties in quantifying individual mineral reactive surface area in a mixture of minerals of greatly varying particle size, possibly due to factors such as dependence of surface area-normalised mineral dissolution rates on particle size and time, or to non-proportionality between rates and BET surface area. 相似文献
15.
Changyi Shi Tiexin Gu Wei Bu Weidong Yan Mei Liu Mingcai Yan 《Geostandards and Geoanalytical Research》2008,32(3):337-345
The Institute of Geophysical and Geochemical Exploration in China recently prepared ten biogeochemical certified reference samples GSB1‐10 (CRMs). The samples are primary agricultural products such as rice, wheat, corn, soybean, cabbage, spinach, tea, powder, chicken and apple. Lyophilisation technology and a high‐alumina ball mill were used to process the samples. Fourteen laboratories and hundreds analysts in China participated in the certification analysis. Over ten reliable analytical methods, predominately ICP‐MS, ICP‐AES and INAA, were used for analysing the samples for fifty‐nine elements. A total of 22477 determinations led to 5136 average data sets. Certified values of fifty‐four elements were assigned. 相似文献
16.
M. Vučnić Vasić J. Kiurski S. Aksentijević U. Kozmidis-Luburić 《International Journal of Environmental Science and Technology》2013,10(5):923-930
Concentrations of heavy metals, pH, and particle size distribution parameters were measured in Dragica stream and Djetinja River water receiving wastewaters from copper rolling mill industry, Sevojno. The concentrations of copper, zinc, lead, and mercury were determined for water samples collected in summer 2009. It was found that Copper Rolling Mill Sevojno was the significant source of water pollution with copper and zinc. Considering that copper rolling mill industry, one of the larger emitters of sulfur dioxide, pollutes the area, the water pH was surprisingly alkaline. The particle size analysis results showed that particles from oil-in-water emulsion evidently got into stream water in spite of the purification devices used. In order to assess the possible relations between the measured parameters, a correlation analysis was performed. The correlation analysis showed a significant positive correlation between the total metal concentrations of copper and zinc, as well as between particle size distribution parameters and the concentration of lead and copper. 相似文献
17.
Development of a New Method of Extraction of Interstitial Water from Low‐Porosity Consolidated Sediments Recovered During Super‐Deep Drilling Projects 
下载免费PDF全文
下载免费PDF全文 Tomohiro Toki Harue Masuda Harunur Rashid Sebastian Hammerschmidt Ryuichi Shinjo 《Geostandards and Geoanalytical Research》2016,40(2):291-300
During the Integrated Ocean Drilling Program (IODP) Expedition 338, several methods were tested for the extraction of interstitial water in consolidated, low‐porosity deep‐sea sediments from Site C0002 in the Kumano Basin. On the basis of those tests, we propose a modified ground rock interstitial normative determination (GRIND) method of extraction of interstitial water. In separate runs of the new method, sediment samples were ground in a ball mill with either ultrapure water or a solution of HNO3. The interstitial water was then extracted with a conventional squeezer. Sufficient solution was extracted by this method to analyse most major and a few minor components of interstitial water that were comparable to those previously reported for samples extracted by the conventional squeezing method. The new method requires much smaller amounts of sediment than that of the conventional method and will be useful for analysis of samples recovered during super‐deep drilling programmes. 相似文献
18.
《Applied Geochemistry》2003,18(11):1733-1750
The Rabbit Lake U mine in-pit tailings management facility (TMF) (425 m long×300 m wide×91 m deep) is located in northern Saskatchewan, Canada. The objectives of this study were to quantify the distribution of As phases in the tailings and evaluate the present-day geochemical controls on dissolved As. These objectives were met by analyzing pore fluid samples collected from the tailings body for dissolved constituents, measuring Eh, pH, and temperature of tailings core and pore fluid samples, conducting sequential extractions on solid samples, conducting geochemical modeling of pore fluid chemistry using available thermodynamic data, and by reviewing historical chemical mill process records. Dissolved As concentrations in 5 monitoring wells installed within the tailings body ranged from 9.6 to 71 mg/l. Pore fluid in the wells had a pH between 9.3 and 10.3 and Eh between +58 and +213 mV. Sequential extraction analyses of tailings samples showed that the composition of the solid phase As changed at a depth of 34 m. The As above 34 m was primarily associated with amorphous Fe and metal hydroxides while the As below 34 m was associated with Ca, likely as amorphous poorly ordered calcium arsenate precipitates. The change in the dominant As solid phases at this depth was attributed to the differences in the molar ratio of Fe to As in the mill tailings. Below 34 m it was <2 whereas above 34 m it was >4. The high Ca/As ratio during tailings neutralization would likely precipitate Ca4(OH)2(AsO4)2:4H2O type Ca arsenate minerals. Geochemical modeling suggested that if the pore fluids were brought to equilibrium with this Ca-arsenate, the long-term dissolved As concentrations would range between 13 and 126 mg/l. 相似文献
19.
A centrifugal mill is a high-power intensity media mill that can be used for ultra-fine grinding, employing centrifugal forces generated by gyration of the axis of the mill tube in a circle. The mill charge motion is quite different depending on the ratio of the gyration diameter to the mill diameter (G / D ratio), varying from a motion similar to that of a conventional tumbling media mill to that of a vibration mill. In this study, a centrifugal mill was constructed with an arrangement where the gyration diameter could be readily adjusted. The batch grinding characteristics of three different minerals (limestone, talc and illite) in water with dispersing agent were investigated at various G / D ratios. It was found that the optimum G / D ratio in terms of the specific energy consumption to give a desired fineness of product was different for the three minerals. This was due to their different reactions to the breakage mechanisms provided by the mill charge motion at varying G / D ratios. The size distributions became progressively narrower at increased grinding times, and particles finer than about 0.1 μm were not detected even for prolonged grinding times. Measurement of specific surface areas indicated that this was not due to an artifact of the size measurements by laser diffractometry. This implies that there is a limitation in which particles finer than 0.1 μm are not produced under the conditions tested in this type of mill, but further investigation is needed for experimental verification of this limit of comminution. 相似文献