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High carbon-chrome iron samples can be decomposed using strong oxidizing acid, mixed acid or by the alkali fusion method under high temperature. These chemical procedures are complex, especially the alkali fusion method, which introduces a large amount of interfering ions such as Na+. Microwave digestion technology is widely used in the pretreatment process of insoluble samples. This pretreatment method combined with Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) has been reported to determine Fe in high carbon-chrome iron. Based on previous studies, a method for the simultaneous determination of silicon, manganese and phosphorus has been established in this study. HNO3 is conducted to digest easy decomposition components in high carbon-chrome iron. HClO4 and HF are then loaded to digest carbides and silicides. Since there is a reduction in the volume of HClO4, the process is stable and safe. Using high carbon-chrome iron standard materials to set up the calibration curve, and Y, In and Bi as internal standard elements, the detection limits of silicon manganese and phosphorus were 0.0017%, 0.0025% and 0.0033%, respectively. Precision and accuracy of this method were verified by using high carbon-chrome iron standard materials of GSB 03-1562—2003, GSB 03-1058—1999 and GSB 03-1059—1999. The results were consistent with the certified values. The relative standard deviations (RSD) are in the range 0.8%-6.0% (n=11), and the relative deviations (RE) are from 0.044% to 0.227%. This method has the advantage of digesting the sample completely, is safe and has a simple operation process and a high degree of accuracy, which can also be used for the determination of several elements in high carbon-chrome iron.

Abstract: Along with China′s economic development, the dissolution of heavy metals in port minerals stockyard has became important contamination sources of soil and water, which can't be ignored. The amount of heavy metal dissolution is related to the species of heavy metals. Through the static soaking test, according to the leaching of heavy metals to determine the typical mineral products and the typical heavy metal factor to study the influence of time, pH and temperature on release of heavy metals in typical products at Tianjin port stockyard. The results showed that the amounts of heavy metals released from lead ore and copper ore were the greatest. Zn, Pb and Cd in the lead ore and Ni in the copper ore were the typical heavy metal factor, and were found to be 1-3 orders of magnitude higher than other heavy metal ions. The concentration of Zn, Pb, and Cd in lead ore increased with time, and the concentration of Ni in the copper ore basically remained stable. The concentration of Zn, Pb and Cd in the lead ore and Ni in the copper ore had no significant differences with the change of pH (3.5 to 7.5). The concentration of Zn, Pb, and Cd in the lead ore increased with temperature (20-40℃). The concentration of Ni in the copper ore showed a downward trend above 30℃. This study preliminarily investigated the basic rule of dissolution of heavy metals in minerals and provides data to support and control the dissolution of heavy metals in the port stockyard.

Abstract: Along with China′s economic development, the dissolution of heavy metals in port minerals stockyard has became important contamination sources of soil and water, which can't be ignored. The amount of heavy metal dissolution is related to the species of heavy metals. Through the static soaking test, according to the leaching of heavy metals to determine the typical mineral products and the typical heavy metal factor to study the influence of time, pH and temperature on release of heavy metals in typical products at Tianjin port stockyard. The results showed that the amounts of heavy metals released from lead ore and copper ore were the greatest. Zn, Pb and Cd in the lead ore and Ni in the copper ore were the typical heavy metal factor, and were found to be 1-3 orders of magnitude higher than other heavy metal ions. The concentration of Zn, Pb, and Cd in lead ore increased with time, and the concentration of Ni in the copper ore basically remained stable. The concentration of Zn, Pb and Cd in the lead ore and Ni in the copper ore had no significant differences with the change of pH (3.5 to 7.5). The concentration of Zn, Pb, and Cd in the lead ore increased with temperature (20-40℃). The concentration of Ni in the copper ore showed a downward trend above 30℃. This study preliminarily investigated the basic rule of dissolution of heavy metals in minerals and provides data to support and control the dissolution of heavy metals in the port stockyard.

High carbon-chrome iron samples can be decomposed using strong oxidizing acid, mixed acid or by the alkali fusion method under high temperature. These chemical procedures are complex, especially the alkali fusion method, which introduces a large amount of interfering ions such as Na+. Microwave digestion technology is widely used in the pretreatment process of insoluble samples. This pretreatment method combined with Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) has been reported to determine Fe in high carbon-chrome iron. Based on previous studies, a method for the simultaneous determination of silicon, manganese and phosphorus has been established in this study. HNO3 is conducted to digest easy decomposition components in high carbon-chrome iron. HClO4 and HF are then loaded to digest carbides and silicides. Since there is a reduction in the volume of HClO4, the process is stable and safe. Using high carbon-chrome iron standard materials to set up the calibration curve, and Y, In and Bi as internal standard elements, the detection limits of silicon manganese and phosphorus were 0.0017%, 0.0025% and 0.0033%, respectively. Precision and accuracy of this method were verified by using high carbon-chrome iron standard materials of GSB 03-1562—2003, GSB 03-1058—1999 and GSB 03-1059—1999. The results were consistent with the certified values. The relative standard deviations (RSD) are in the range 0.8%-6.0% (n=11), and the relative deviations (RE) are from 0.044% to 0.227%. This method has the advantage of digesting the sample completely, is safe and has a simple operation process and a high degree of accuracy, which can also be used for the determination of several elements in high carbon-chrome iron.

Based on field research at port mineral yard, leaching of heavy metals as an important port soil, water pollution cannot be ignored. The rules of typical pollutants were simulated by the micro-universe model. In this study, the soil and water samples from 7 heavy metals storage yards of Tianjin Port have been investigated, revealing high Cd pollution in soil. Aquatic microcosm was used to simulate the chemical behavior of lead and cadmium in Tianjin port, and the internal transportation law was found by using the fugacity-based multimedia environmental mathematical model. The results of the model and experiment were consistent, showing that this model is suitable. The results of the model suggest that 61% of the cadmium in the system was sunk into sediment, the rest flowing out with water, and 99% of the lead was sunk into sediment, showing that for cadmium and lead, settling was the main transport process in the aquatic environment, especially for lead. The impact of minerals stored in the open areas is significant, and should be stored in containers without any direct contact with rain. Also, the pollution channel should be kept closed.

The consumption of raw ore and ore concentrate and the product of tailings are currently very high in China. The hazardous and toxic contaminants released from mineral products have become a general environmental problem. In this paper the components of contaminants in mineral products and recent research involving them is briefly introduced. The four different leaching simulation experiments of humidity cell, column, static immersion and extraction are discussed in this paper. The humidity cell experiment can simulate natural weathering reactions of products and determine the dissolution rates of contaminants and related products. The column experiment can simulate hydrometeor or drench conditions to provide the kinetic basis for both adsorption and desorption. The static immersion experiment can simulate immersion processing in water, in order to study the release law and related products. The extraction experiment can be used to conduct chemical morphological analysis for contaminants to evaluate the mobility and stability of contaminants in a medium. Various impact factors for contamination dissolution are summarized. Influencing factors in order of strong to weak were pH, leaching or soaking time, temperature, and solid-liquid ratio and ore particle size. In most cases, the higher the pH, the longer leaching or soaking time, the higher the temperature, the smaller solid-to-liquid ratio and the smaller the mineral products particle size, the easier to leach contaminants. Leaching of contaminants was found to be a long-term and latent process. There was a series of physical and chemical reactions that took place inside the products, which indicated the different leaching rules with the diffusion effect. At present, the object of this study is mainly focused on tailings, however, the leached contaminants from the stacked raw ore and ore concentrate products for human use need further research. Leached contaminants need to be predicted and assessed in order to take effective measures to control or manage pollution from mineral ores.

Abstract Background Probucol is a unique hypolipidemic agent that decreases high density lipoprotein cholesterol (HDL-C). However, it is not definite that whether probucol hinders the progression of atherosclerosis by improving HDL function. Methods Eighteen New Zealand White rabbits were randomly divided into the control, atherosclerosis and probucol groups. Control group were fed a regular diet; the atherosclerosis group received a high fat diet, and the probucol group received the high fat diet plus probucol. Hepatocytes and peritoneal macrophages were isolated for [3H] labeled cholesterol efflux rates and expression of ABCA1 and SR-B1 at gene and protein levels; venous blood was collected for serum paraoxonase 1, myeloperoxidase activity and lipid analysis. Aorta were prepared for morphologic and immunohistochemical analysis after 12 weeks. Results Compared to the atherosclerosis group, the paraoxonase 1 activity, cholesterol efflux rates, expression of ABCA1 and SR-BI in hepatocytes and peritoneal macrophages, and the level of ABCA1 and SR-BI in aortic lesions were remarkably improved in the probucol group, But the serum HDL cholesterol concentration, myeloperoxidase activity, the IMT and the percentage plaque area of aorta were significantly decreased. Conclusion Probucol alleviated atherosclerosis by improving HDL function. The mechanisms include accelerating the process of reverse cholesterol transport, improving the anti-inflammatory and anti-oxidant functions.