Effects of Mill Speed and Air Classifier Speed on Performance of an Industrial Ball Mill

2021 ◽  
Vol 3 (1) ◽  
pp. 28-37
Author(s):  
Fazeel Ahmad ◽  
Junaid Ahmad Qayyum ◽  
Usman Asghar ◽  
Asad Ali ◽  
Ayesha Masoom

Nowadays, ball mills are widely used in cement plants to grind clinker and gypsum to produce cement. The research focuses on the mill speed as well as air classifier speed effect on the two compartment Cement ball mill performance in terms of Blaine, Sulphur trioxide contents, mill power, mill residue and mill residence time. Special importance was assigned to the study of the specific surface area and the surface area production rate, both during the variation with the mill speed and the air classifier speed. Within the content of this work, sampling campaigns were organized around a cement grinding circuit and varying cement ball mill speed as well as an air classifier speed at various dosage feed rate. The fact that such an examination has not been made previously by using industrial data rather than lab scale makes this work unique. The fineness is measured in terms of Blaine number. Mill speed and air classifier speed were the investigating parameters. It was deduced that depending on the speed of mill and air classifier, their effects on Blaine, SO3, mill power and mill performance were varied, ultimately all of them improved the performance of grinding and classification operations. The rapid expansion of ceramic wastes in China has raised great many interests in their sustainable uses in building materials The micro ceramic powder can be taken as a supplementary cementitious material to replace cement up to 40% for tuning the microstructure and mechanical properties of blend cement materials. The Blaine quality dictates strength, setting time and overall performance of cement. Optimum performance of ball mill could potentially refine Blaine fineness, thereby improving the cement quality. This study investigates the effects of separator speed and mill speed on Blaine fineness, mill residue, consumed power. Five speed levels used in closed cycle grinding mill are 200, 400, 600, 800 and 1000 rpm. The capacities were determined to obtain product Blaine surface areas in the limits between 2000 cm2 / gram and Variations in clinker feed rate, mill speed and separator speed could proportionally impact the grain quality of Blaine. When the separator speed is increased from 850 to 900 rpm the Blaine is increased from 2800 to 3000 cm2/g and mill residue decrease from 15 to 10 microns. Therefore, optimum parametric combination could reduce power consumption while improving the cement quality. Knowledge of effects of parametric variations on the quality of end product could be helpful for controlling product quality. Furthermore, proper grinding of clinker produces fine Blaine at first place and reduces the need for recycling of coarse grains.

2021 ◽  
Vol 13 (3) ◽  
pp. 168781402199496
Author(s):  
Tongqing Li ◽  
Zixin Yin ◽  
Guiyi Wu

Ball mill is the widely used comminution device for the size reduction of iron ore particles, yet the underlying mechanisms of heat transfer and thermal breakage inside the mills heretofore are not deeply understood. Therefore, the Discrete element method was carried out to study the effect of operating parameters on charge temperature, and the batch grinding experiments of iron ores were conducted to verify the heating temperatures using a laboratory ball mill. Results show that increasing mill speed will result in the charge temperature increasing initially and then decreasing. The temperature fields of the charge and load behavior remain approximately the same for the different ball filling. The main findings of this study are that the heating temperature can contribute to enhancing the breakage behavior of iron ore particles, and correspondingly the optimal feed sizes for different heating temperatures are determined to be 2.48 mm, 2.63 mm, 2.78 mm, and 3.59 mm, respectively.


Author(s):  
Zixin Yin ◽  
Yuxing Peng ◽  
Tongqing Li ◽  
Zhencai Zhu ◽  
Zhangfa Yu ◽  
...  

The wear of lifter in ball mill directly affects the grinding efficiency and economic cost. However, how to evaluate the variation of wear process and predict the wear distribution of lifter is poorly developed. To this end, a laboratory-scale ball mill was used to evaluate the variation of wear process of the lifter in different milling conditions of mill speed, ball filling, grinding media size and shape. Besides, a wear prediction method was used to compare and validate the experimental results. The experimental results showed that the Abbott-Firestone curve can evaluate the lifter surface topography. The wear rate of the lifter specimen is increased first and then decreased with mill speed and grinding media size. Increasing ball filling will increase the wear rate, and the grinding media shape of ball has a maximum wear rate. The wear characteristics of the lifter specimen are consisting of impact pit, indentation, plastic deformation and scratch. Furthermore, the discrete element method (DEM) simulation showed that the wear behavior on the upper surface is higher than that on the side surface of the lifter. The DEM simulation with Archard wear model is an effective tool to investigate the wear distribution on the lifter, which is in good consistent with the wear behavior measured by the experiment.


2019 ◽  
Vol 8 (4) ◽  
pp. 7695-7698

The article presents the results of studies of grindability of zeolite-containing rocks in ball mills with different grinding conditions. The results of studies of grindability of zeolite-containing rocks, optimization of the grinding process and determination of the specific productivity of industrial mills are presented. From a practical point of view, the data obtained can reduce the energy consumption of the grinding process of zeolite-containing rocks and increase the values of equipment efficiency and improve the quality of the finished product.


2021 ◽  
pp. 1050-1059
Author(s):  
И. Л. Сизова ◽  
Н. С. Орлова

В статье рассматриваются социальные процессы, сопровождающие реализацию политики «активного долголетия» в российской социальнотрудовой сфере. В первом разделе статьи кратко представляются основы концепции «активного долголетия» и обсуждаются возможные социальные механизмы ее применения. Особое место здесь отводится анализу социальных прав, которые формируют основу для разных моделей развития общественного благосостояния и качества жизни населения. Во втором разделе на базе парадигмы конструктивизма в социальных науках и теории символической власти П. Бурдьё предлагается авторский вариант изучения структур восприятия и оценивания населением реализованных государственных реформ. В третьем разделе представлены результаты эмпирического анализа серии полуструктурированных интервью с основными субъектами социально-трудовой сферы и текстов обращений граждан в органы государственной власти. В заключение интерпретируется символическая борьба вокруг восприятия политики «активного долголетия» в России. Авторы приходят к выводу о том, что ожидается новый всплеск программ социальной помощи пожилым и рост пассивности в их трудовом поведении. The article examines the social processes accompanying implementation of the policy «active aging» in the Russian social and labor spheres. The basic concepts of «active aging» are briefl y introduced and possible social mechanisms of its application are discussed in the first section of the article. Special importance is given to the analysis of social rights which form the basis for different models of the development of public welfare and the population’s quality of life. In the second section, author’s version of studying the perception and assessment structures by the population of the implemented reforms of the State are proposed on the basis of the paradigm of constructivism in the social sciences and the theory of symbolic power by P. Bourdieu. In the third section the results of an empirical analysis of a set of semi-structured interviews with the main subjects of the social and labor spheres and the texts of citizens’ appeals to government bodies are presented. In conclusion, the symbolic struggle around the perception of the «active aging» policy in Russia is interpreted. The authors conclude that a new surge in social assistance programs for the elderly and an increase in passivity in their work behavior are expected.


Nafta-Gaz ◽  
2021 ◽  
Vol 77 (5) ◽  
pp. 299-312
Author(s):  
Marek Janiga ◽  
◽  
Małgorzata Kania ◽  
Agnieszka Wciślak ◽  
Karol Spunda ◽  
...  

The aim of the work, the results of which are presented in the article, was to evaluate the influence of the method of sample preparation on the results of pyrolytic analyses: RockEval, Py-GC-FID (gas chromatography with FID detector) and Py-GC-IRMS (isotope mass spectrometry with gas chromatography). Mortars and ball mills are most often used to grind the samples. Three rock samples with a higher organic carbon content (shales) and five with a lower organic carbon content (including two samples of dolomites and three of anhydrites) were prepared. The rocks were homogenized and divided into three parts. Each part was ground: by hand in a mortar, in a ball mill for 5 minutes, and in a ball mill for 15 minutes. A total of 24 RockEval analyses, 48 Py-GC-FID analyses (two pyrolysis temperatures corresponding to RockEval pyrolysis conditions) and 24 Py-GC-IRMS analyses were performed. The grinding of the samples for the RockEval analyses is insignificant. The differences in the results seem to indicate the influence of the analysis error and the nature of the sample. For the Py-GC-FID methodology, the influence of milling on the results of desorption carried out at the temperature of 300ºC for most of the tested samples can be considered insignificant and negligible. At the temperature of 500ºC, various types of samples show some correlations, but they are insufficient to reject one of the methods of sample preparation. Therefore, it is important to analyze the results comprehensively, taking into account both the group composition and the distribution of pyrolysis products. In the case of the isotopic composition analyses (Py-GC-IRMS), also no differences in δ13C values related to different types of grinding samples can be found. Summarizing, all the results show a negligible influence of the method of grinding the samples on the results of pyrolysis analyses. Nevertheless, it is important that only one method of sample preparation is used for a separate sample series.


2014 ◽  
Vol 682 ◽  
pp. 32-34 ◽  
Author(s):  
N.S. Belousova ◽  
O.A. Goryaynova ◽  
E.V. Melnikova

In this paper the results of alumina aqueous suspension disaggregation with the help of bead and ball mills are shown. The changing of maximum particle size for50 wt. % and 90 wt. % of powder (from lowest to highest size) in suspension dispersed by a bead mill for one hour and ball mill for 48 hours was fixed. In order to achieve powder parameters given by the manufacturer disaggregating process sets was defined.


2020 ◽  
Vol 67 (4) ◽  
pp. 1155-1167
Author(s):  
Pavle Radanov ◽  
Ivana Lešević ◽  
Pavle Brzaković ◽  
Dragan Pajić

In the Republic of Serbia, on March 15 th , 2020 Government decided to declare a state of emergency due to the Covid-19 pandemic. One of the measures was a movement ban for people over 65 in urban areas and those over 70 in rural areas. This research should indicate how people over 65 in urban areas have endured this situation, especially in relation to the same population in rural areas, as well as implications of the movement ban on the quality of life of the elderly population. Special importance is given to the rural population engaged in agriculture. A tool of data collection in this research was anonymous survey. Respondents' answers were statistically processed, which led to clear conclusions about the large negative consequences for the elderly population, including the agricultural activities in rural areas. Covid-19 is still present, which opens further questions related to the quality of life of the elderly population, if necessity for similar measures recurs in the future.


2019 ◽  
Vol 8 (2S3) ◽  
pp. 1000-1003 ◽  

In this paper, a study on the effect of the control on the wall pressure as well as the quality of the flow when tiny jets were employed. The small jet aimed to regulate the base pressure at the base region of the suddenly expanded duct and wall pressure distribution is carried out experimentally. The convergent-divergent (CD) nozzle with a suddenly expanded duct was designed to observe the wall pressure distribution with and without control using small jets. In order to obtain the results with the effect of controlled four tiny jets of 1 mm diameter located at a ninety-degree interval along a pitch circle diameter (PCD) of 1.3 times the CD nozzle exit diameter in the base, region was employed as active controls. The Mach numbers of the rapidly expanded are 1.5. The jets were expanded quickly into an axis-symmetry duct with an area ratio of 4.84. The length-todiameter (L/D) ratio of the rapid expansion duct was diverse from 10 to 1. There is no adverse effect due to the presence of the tiny jets on the flow field as well as the quality of the flow in the duct


Author(s):  
Maria Cristina Dijmarescu

Destructive and non-destructive testing of materials present a rapid expansion given by the increase in market demand caused by the desire to obtain an increasingly better quality of products. The continuous increase in quality demands leads directly to the need to implement and modernize the techniques, methods, and equipment used for quality control. Consequently, the need for product testing services has a rapid growth. This paper presents the strength and weaknesses of implementing IT tools for the estimation of the measurement uncertainty in testing laboratories and the impact of these tools on the economic part


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