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In this study, two different copper nickel ores produced in China and South Africa were taken as the research object, and the influence of grinding medium type on the flotation behavior of copper nickel ores was studied. The results show that the flotation recoveries of Cu and Ni of JC copper nickel ore from China after grinding with stainless steel medium are higher than those of cast iron medium, the grade of Cu is significantly improved, the floating speed of Ni is slower, and the floating amount of serpentine is greatly increased. However, the copper and nickel flotation recovery of NK copper nickel ore of South Africa after grinding with stainless steel medium is significantly lower than that of iron casting medium, and the mass draw of sulfide mineral and chromite is increased, while the mass draw of talc is significantly reduced. Galvanic effect in grinding process and hydroxyl complex produced by grinding of cast iron medium are important factors affecting flotation behavior of copper nickel sulfide minerals and gangue minerals. The difference in mineral composition of the two ores, to some extent, causes the difference in the influence of the above factors on the flotation behavior of the two ores. The gangue mineral of JC copper nickel ore is mainly serpentine. The Fe produced in the grinding process of cast iron medium has a living effect on serpentine, which makes the serpentine float up in a large amount in the flotation process and reduces the concentrate grade. The effect of Gavanic on the flotation behavior of JC copper nickel ore is significant. The proper oxidation of copper minerals during grinding with stainless steel medium can improve the copper flotation speed and recovery rate, but has a negative impact on the flotation speed of nickel minerals. The content of talc in NK copper nickel ore reaches 7%. Due to the strong hydrophobicity of talc and the adsorption and consumption capacity of the foaming agent and collector, a large proportion of the foaming agent and collector of NK copper nickel ore are consumed by talc when grinding with stainless steel medium, resulting in a significant reduction in the flotation amount of sulfide minerals, but the flotation speed of copper sulfide minerals is still improved to a certain extent by the effect of gavanic. The cover of iron hydroxy speicies produced by grinding of cast iron medium on the surface reduces the absorption consumption of talc for frother and collector to a certain extent, thereby increasing the mass draw of nickel sulfide and pyrrhotite in the ore. [ABSTRACT FROM AUTHOR]

With the continuous advancement of environmental protection policies in China, the resource utilization of steel slag is imminent, it is very necessary to develop large-scale, high-efficiency steel slag grinding technology and equipment. A large-scale steel slag roller press with rack roller surface was adopted and the service life of the rack roller is expected to reach more than 10 000 hours. The iron removal technology of the roller press pre-grinding system is developed, and the cake of the roller press passes through a dedicated split type tube iron remover with efficient iron removal effect, the influence of wear and installation angle of the iron remover on the iron removal effect can be effectively solved and the energy consumption of the steel slag roller press for pre-grinding can be reduced. Through repeated simulation and comparison of the structure and rotor of the powder separator, structure of the dynamic powder separator has been optimized and improved,and the combined separation technology for high-fine materials has been researched and developed, which reduces pressure loss and ensures that the materials are controlled below 45 µm without being thick, and the specific surface area of steel slag powder is adjustable flexibly at 350~450m²/kg. [ABSTRACT FROM AUTHOR]

Grinding is an important link in the process of mineral processing. It plays a vital role in mineral processing by optimizing the grinding process, improving the quality of grinding products and ensuring the follow-up operation indicators. In this paper, the Python language, intelligent theoretical control technology and mineral processing were combined to solve the problem of ore feeding control in mineral processing. Using error factor analysis, an extended control algorithm was designed. The NumPy library and data collected from the Yuan YangMou concentrator in China were used to quantitatively analyze the factors affecting the error of electronic belt scales. This paper introduces the use of Kalman filtering for electronic belt scale weight data to reduce the effect of noise and hence reduce errors. The factors affecting the process of mill feeding are also analyzed. The core ideas and methods of fuzzy control theory are summarized, and a Python-based fuzzy controller suitable for the mill feeding process that improves the overall robustness and accuracy of feeding system is implemented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pre-grinding has a good promoting effect on coal gasification slag flotation. • Compared with primary flotation, secondary flotation has better flotation performance and can obtain higher ash content of tailings. • The tailings yield reach 37.67%, with an ash content of 91.77% and a loss on ignition of 8.23%. • The tailings products met the requirements of Class III fly ash. Coal gasification fine slag (CGFS), a solid waste byproduct of the coal gasification process, is predominantly treated through landfilling or stacking, with limited large-scale industrial applications. Given the high ash content, high porosity, and numerous continuous components of CGFS, this study focuses on a dry powder CGFS sourced from northern China. By analyzing the material composition, particle size distribution, surface morphology, and internal structure, a secondary-flotation decarbonization method based on pre-grinding was innovatively developed and the optimal dosage of reagents was determined. Experimental results indicate that fine grinding exposes the residual carbon surface of CGFS, significantly enhancing its floatability. With a grinding time of 3.5 min, the consumption of collector (Oil #3, a lightweight alkyl compound) in roughing flotation was 14 kg/t, while foaming agent (MIBC, methyl isobutyl carbinol) consumption was 3 kg/t. In scavenging flotation, Oil #3 consumption was 14 kg/t, and MIBC consumption was 1.5 kg/t. The concentrate yield was 3.20 %, with an ash content of 26.91 %. The tailings mineral content reached 37.67 %, with an ash content of 91.77 % and a loss on ignition (LOI) of 8.23 %. The tailings products met the requirements of Class III fly ash. [ABSTRACT FROM AUTHOR]

Scholars have long recognized the importance of organic artifacts to an improved understanding of the economic and social behavior of Palaeolithic hominins. However, in contrast to archaeological studies in other parts of the world, osseous industries from China have received only limited attention. As one of the first steps aiming at tipping this balance, the current paper examines, therefore, a shaped boar tusk—one particular element of hunter-gatherers' tool kit at Shuidonggou Locality 12 (SDG12). Morphological and metrical comparisons of the tusk with both paleontological specimens and bone artifacts from the same site demonstrate that wear pattern on one of the dentin surfaces of the tooth is not significant different from occlusal attritions in living animals, while linear striations on the other dentin facet are most probably artificial grinding marks formed by prehistoric toolmakers in attempts to manufacture a scraper. The tusk specimen from SDG12 represents the first evidence of a ground tooth in Upper Palaeolithic China. The current study indicates that hominins in Shuidonggou area had achieved a deepened understanding of physical properties of osseous material available in environs and ultimately broadened their range of raw material selection by adding a particular element to the inventory of subsistence tools. [ABSTRACT FROM AUTHOR]

Roasting is the traditional heat treatment of oat kernels before milling in China. The effects of roasting and milling methods on the physicochemical properties of oat flour and the quality of the steamed oat cake have not been explored. Roasting treatment caused a looser structure of the oat grain, which made the oat grain easier to crush. Stone milling induced severe damage (92 g/kg) and aggregation of starch granules, resulting in the highest total starch hydrolysis rate of oat flour and the highest total gas volume of raw oat batter. However, the pore expansion capacity was restricted, resulting in the minimum specific volume and the highest hardness of steamed oat cake. Ultrafine milling produced a more uniformly particle size distribution of raw and roasted oat flour and the steamed oat cake prepared with ultrafine-milled raw oat flour had the maximum specific volume and minimum hardness, 2.75 mL/g and 6.01 N. Pulverizer milling resulted in the lowest solubility index and the lowest starch hydrolysis rate of raw and roasted oat flour. Raw whole oat flour prepared by ultrafine milling or pulverizer milling gave softer steamed oat cakes with higher volume or slower starch degradation, respectively. • Stone milling induced severe damage and aggregation of starch granules. • Pulverizer milling led to the lowest solubility index and starch hydrolysis rate. • Steamed oat cake made of ultrafine-milled raw flour had the maximum specific volume. • Roasting reduced gas production capacity and resulted in uneven gas chamber structure. • Raw oat flour prepared by ultrafine milling is more suitable for making steamed oat cake. [ABSTRACT FROM AUTHOR]

This paper makes research on solving the problem in China concerning the suitable particle size for flotation and the optimum particle size of the concentrate required by the subsequent Bayer process. Grinding experiments under different conditions and flotation tests had been used to investigate the comminution property of bauxite and aluminosilicate as well as their separation by flotation. The results showed that different kinds of grinding medium led to different grinding effects, the following being the order of the selective grinding effect: (column+ball)>ball>rod, and the separation between Al and Si in bauxite has been improved after selective grinding. It is indicated that the crystal structural difference between diaspore and aluminosilicate leads to their difference of comminution property. A demo plant built by the novel process of ‘selective grinding–flotation’ had been successfully commissioned in China since 2003. [ABSTRACT FROM AUTHOR]

Objectives: To study the characteristics and the factors influencing the occurrence of the Hand-Arm Vibration Syndrome (HAVS) for a population grinding handheld workpieces in a subtropical environment., Methods: A total of 803 workers grinding handheld workpieces formed the exposure group and 464 workers not exposed to hand-transmitted vibration (HTV) were recruited as the non-exposed group within the same factory in a subtropical climate area. The basic personal information and clinical symptoms reported were collected by trained physicians using a questionnaire and representative measurements were made of the HTV exposure levels and dose., Results: The average HTV exposure dose A(8) was measured as 5.3 ± 2.0 m/s 2 . The proportion of grinders reporting finger blanching was 15.4% while it was 27.5% for finger numbness. Among the non-exposed group, that proportion was 0% and 6.3% respectively. There was a positive association between the vibration exposure duration and the occurrence of finger blanching, finger numbness and finger coldness. Riding a motorcycle to work was also identified as a factor that could contribute to a higher prevalence of finger blanching among the exposed workers, the OR value was found to be 1.75 (1.12, 2.75)., Conclusions: Workers exposed to vibration in a subtropical area can also present evidence of finger blanching in addition to neurological symptoms. The reported rate of HAVS was positively associated with the exposure duration. And the levels of the duration of exposure relative to symptoms of vibration white finger in a subtropical temperate environment exposed to a high-frequency vibration might be deemphasized by the current ISO weighting. Motorcycle transportation to work was identified as a factor that could influence the development of the HAVS among the exposed population of grinders.