Use of dry grinding process to increase the leaching of gold from a roasted concentrate containing hematite in the thiosulfate system

2021 ◽  
pp. 105582
Author(s):  
Yanhe Nie ◽  
Jianghao Chen ◽  
Qiang Wang ◽  
Canyu Zhang ◽  
Changliang Shi ◽  
...  
Keyword(s):  
Grinding Process ◽  
Dry Grinding

Study on MQL in Point Grinding Process for Green Manufacturing

2010 ◽  
Vol 97-101 ◽  
pp. 2356-2360 ◽  
Author(s):  
Shu Dong Xiu ◽  
Zhi Jie Geng
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
Ground Surface ◽  
Green Manufacturing ◽  
Cooling Condition ◽  
Geometric Configuration ◽  
Grinding Process ◽  
Pressure Condition ◽  
Dry Grinding ◽  
Grinding Power

In point grinding process, the contact area of point grinding is much smaller than that of conventional cylindrical grinding under same conditions, so the grinding power and heat to measure is lower and the cooling condition is improved obviously. For green manufacturing, the point grinding process has the significance to reduce the consumption of grinding fluid and improve ground surface integrity and greenness. This study analyzes the geometric configuration of the contact area between wheel and workpiece in point grinding process, establishes the geometric and mathematic models of the contact area, and investigates the relations between the grinding parameters and the grinding power by the simulations. The MQL and semi-dry point grinding experiments are performed on the ground surface integrity. These investigations show that the MQL and semi-dry grinding can be achieved in point grinding process under less contact area and higher jet pressure condition for the high greenness demand.

Effects of dry grinding on pyrophyllite

Clay Minerals ◽  
1988 ◽  
Vol 23 (4) ◽  
pp. 399-410 ◽  
Author(s):  
J. L. Pérez-Rodríguez ◽  
L. Madrid Sánchez del Villar ◽  
P.J. Sánchez-Soto
Keyword(s):  
Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Grinding Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dry Grinding ◽  
Scanning Electron ◽  
Area Data

AbstractDry grinding of pyrophyllite (Hillsboro, USA) has been studied by X-ray diffraction (XRD), specific surface area measurements (BET) and scanning electron microscopy (SEM). At the beginning of the grinding process, some effects such as delamination, gliding and folding of the layers, and decrease in particle size were detected by SEM and XRD, resulting in a large increase in specific surface area, up to a maximum of ∼60 m2·g−1. Marked changes in the structure take place between 30 and 32 mins grinding. Longer grinding times increase the degree of disorder and SEM and specific surface area data suggest that aggregation occurs. XRD results indicate that some residual order persists in the degraded structure.

Effect of Mechanical Activation on the Electrochemical Behavior of MnO2

2013 ◽  
Vol 334-335 ◽  
pp. 369-374
Author(s):  
G.A. Kozhina ◽  
A.N. Ermakov ◽  
V.B. Fetisov ◽  
A.V. Fetisov ◽  
K. Y. Shunyaev ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Mechanical Activation ◽  
Ball Mill ◽  
Electrochemical Behaviour ◽  
Grinding Process ◽  
Carbon Paste ◽  
Mechanochemical Effect ◽  
Dry Grinding ◽  
Oxide Particles ◽  
Electroactive Electrode

Electrochemical behaviour of mechanoactivated β-MnO2 powders has been studied by the method of cyclic voltammetry with a carbon-paste electroactive electrode. Mechanical activation was carried out by dry grinding in an AGO-2 planetary ball mill. It was found that the grinding process results in a mechanochemical effect in the surface layer of the oxide particles: Mn (IV) cations are reduced to Mn (III). Voltammetry test detects that mechanical activation of β-MnO2 leads to a new state, which is characteristic for the γ-modification of manganese dioxide (β-MnO2 γ-MnO2).

Experimental Investigation on Dry Point Grinding Process Based on Green Manufacturing

2010 ◽  
Vol 431-432 ◽  
pp. 470-473
Author(s):  
Shi Chao Xiu ◽  
Zhi Jie Geng ◽  
Guang Qi Cai
Keyword(s):  
Surface Integrity ◽  
Contact Area ◽  
Point Contact ◽  
Ground Surface ◽  
Green Manufacturing ◽  
Depth Of Cut ◽  
Grinding Process ◽  
Cooling Conditions ◽  
Dry Grinding ◽  
Grinding Power

Due to point contact cause, the point grinding process have the lower grinding power and heat to measure and the better cooling conditions. For green manufacturing, the point grinding process has the significance to reduce the consumption of grinding fluid and improve the ground surface integrity and the process greenness. This study analyzes the geometric configuration of the contact area between the wheel and the workpiece in point grinding process, establishes the geometric and mathematic models of the contact area, and investigates the relations between the grinding parameters. The dry point grinding experiments are performed on the ground surface integrity. These investigations show that the dry grinding can be achieved in point grinding process under less depth of cut and the higher grinding speed for the high machining greenness demand.

scholarly journals Effect of Carbon Content in Stainless Steels on Quantity of Grinding Energy

2014 ◽  
Vol 14 (3) ◽  
pp. 45-52
Author(s):  
R. Wójcik
Keyword(s):  
Carbon Content ◽  
Stainless Steels ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Surface Layers ◽  
Abrasive Grains ◽  
Dry Grinding ◽  
Different Types ◽  
Grinding Technique ◽  
Special Parameter

Abstract The paper presents a study of the process of grinding stainless steels with different carbon contents. Verified the size and scope of the energy which is introduced in the surface layers for different types of abrasive grains and binders. The influence of parameters in plunge grinding process was considered in studies. The energy ratio was used for this purpose, which was calculated by multiplying energy and time of grinding wheel contact with the workpiece. To investigate influence of different carbon content on the level of energy density generated during grinding process special parameter Bp have been evaluated. The grinding tests were conducted in dry grinding technique.

Study on the surface micro-topography in pre-stressed dry grinding process

2017 ◽  
Vol 8 (2) ◽  
pp. 83
Author(s):  
Yansheng Deng ◽  
Xiaoliang Shi ◽  
Shichao Xiu ◽  
Minghe Liu
Keyword(s):  
Grinding Process ◽  
Dry Grinding ◽  
Micro Topography

Experimental study on grinding wheel radial wear in surface grinding of steel CrV12 using a zonal centrifugal coolant provision system

2016 ◽  
Vol 230 (12) ◽  
pp. 1452-1461 ◽  
Author(s):  
Jarosław Sieniawski ◽  
Krzysztof Nadolny
Keyword(s):  
Experimental Studies ◽  
Careful Consideration ◽  
Surface Grinding ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Wheel Wear ◽  
Contact Conditions ◽  
Dry Grinding ◽  
Favorable Conditions ◽  
The Impact

The tribology of the grinding process can be considered in the context of a tribosystem, in which the main structural elements (grinding wheel, workpiece, grinding fluid, and environment) are interrelated and interdependent. One of the most important factors influencing the contact conditions of these listed elements of the grinding process tribosystem are the proper selection of grinding fluids and anti-adhesive substances, as well as careful consideration of how they are applied. This article describes a new zonal centrifugal coolant provision system as well as the results of experimental studies conducted into its use. The aim of these experiments was to determine the impact of the system of grinding fluids provision on grinding wheel radial wear in the surface grinding process of steel CrV12. Reference methods within the described studies consisted of dry grinding and grinding using the flood method, among others. The obtained results of the experiment revealed that the use of a zonal centrifugal coolant provision system enabled the acquisition of a similar radial wear rate of the grinding wheel at 90% reduction of grinding fluids flow rate, compared with flooding method. It was also demonstrated that in the most favorable conditions, it is even possible to significantly reduce the intensity of the radial wheel wear, compared with the conventional method.

scholarly journals Experimental Studies on the Centrifugal MQL-CCA Method of Applying Coolant during the Internal Cylindrical Grinding Process

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2383 ◽  
Author(s):  
Krzysztof Nadolny ◽  
Seweryn Kieraś
Keyword(s):  
Hybrid Method ◽  
Experimental Studies ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Cylindrical Grinding ◽  
Minimum Quantity ◽  
Dry Grinding ◽  
Internal Cylindrical Grinding ◽  
Cooling And Lubrication

This paper presents the results of experimental research concerning the possibility of supporting the cooling function during internal cylindrical grinding using the minimum quantity lubrication (MQL) method by additional delivery of a compressed cooled air (CCL) stream. The article presents a description of a hybrid method of cooling and lubrication of the grinding zone integrating centrifugal (through a grinding wheel) lubrication with the minimum quantity of lubricant and cooling with a compressed cooled air stream generated by a cold air gun (CAG). The methodology and results of experimental studies are also presented in detail, with the aim of determining the influence of the application of the hybrid method of cooling and lubrication of the machining zone on the course and results of the internal cylindrical grinding process of 100Cr6 steel in comparison with other methods of cooling and lubrication, as well as compared with dry grinding. The research results obtained using the described hybrid method of cooling and lubrication of the grinding zone are related to the results obtained under the conditions of centrifugal MQL method, cooling with a stream of CCA, cooling and lubrication with a stream of oil-in-water emulsion delivered using the flood method, and dry grinding. The efficiency of the grinding process is evaluated (based on the average grinding power Pav, grinding wheel volumetric wear Vs, material removal Vw, and grinding ratio G), along with the thermal conditions of the process (based on the analysis of thermograms recorded by infrared thermal imaging method), the textures of machined surfaces (based on microtopography measured by contact profilometry), the state of residual stress in the surface layers of workpieces (determined by X-ray diffraction method), and the state of the grinding wheels’ active surfaces after grinding (based on microtopography measured by laser triangulation and images recorded with a digital measuring microscope). The obtained results of the analyses show that the application of the hybrid method allows for the longest wheel life among the five compared grinding methods, which is about 2.7 times the life of grinding wheels working under the flood cooling and centrifugal MQL methods, and as much as 8 times the life of grinding wheels working under the conditions of CCA only and dry grinding.

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