PDF | Chromite ore processing residue (COPR) is a hazardous waste because of leachable chromium, especially Cr(vi). ... However, in the freeze–thaw cycle experiments, the compressive strength of ...
Chromite ore processing residue (COPR) is a hazardous waste because of leachable chromium, especially Cr(vi). Therefore, ascorbic acid (AA) and blast furnace slag (BFS) have been used to detoxify and solidify COPR. ... However, in the freeze-thaw cycle experiments, the compressive strength of the solidified bodies consistently remained …
This study has focused on reducing the carbon emissions and energy consumption for producing ferrochrome, an essential component in stainless-steel manufacturing. The …
Chromite ore processing residue (COPR) is a hazardous waste because of leachable chromium, ... The compressive strength of the solidified specimens in the control group reached a maximum value (99.21 MPa) after 10 freeze–thaw cycles, and a minimum value (86.91 MPa) after 50 freeze–thaw cycles. Moreover, the compressive …
Chromite ore processing residue (COPR) is a hazardous waste because of leachable chromium, ... The compressive strength of the solidified specimens in the control …
(a) Compressive strength machine; (b) samples stage; (c) pellet sample; (d) schematic diagram of compression test. The detection method of iron valence state is as follows. First of all, a weak acid, o-phenanthroline-ammonium chloride, is employed to …
The product prepared has a relatively high compressive strength. Abstract. Chromite ore processing residue (COPR), a waste produced in high lime chromium salt production process using chromite, contains a fraction of leachable Cr(VI) which is harmful to humans and environment. It is of great emergency to solve the pollution of residues ...
Chromite ore processing residue (COPR) is a typical hazardous waste, ... According to the optimal conditions of the single-factor experiment, the highest compressive strength of 147.6 MPa was obtained after using the water glass modulus 1.0, liquid–solid ratio 0.28, alkali–solid content 8%, curing temperature 45 °C. ...
At all basicity values, the strength increases gradually with an increase in time from 10 to 30 minutes. A maximum average CCS of 195.3 is observed at 0.20 basicity and a residence time of 30 minutes. However, the recommended compressive strength for the pellets to be used in arc furnaces for the reduction process is around 100 kg/pellet.
The compression strength of the stone is carried out to determine the compressive strength of the stone. To perform this test take 6 test blocks of dimensions 10cmx10cmx10cm are taken. These blocks are then covered with plaster of Paris subjected to load in the compression testing machine one by one.
Typical Chromite Sand Testing • South African Chromite Sand is the world standard for metalcasting and foundry applications, however there can ... • Transverse tensile strength and compressive strength can also be measured and is more commonly seem in Europe and Asia. Gauge on tensile testing equipment and standard AFS tensile specimens .
This work examines the compressive strength of natural stones, as estimated by Uniaxial compressive strength tests (UCS) and respective non-destructive tests results (Schmidt Hammer Rebound test, SHR, or an Ultrasonic Pulse Velocity transmission, UPV). In practice, aiming to correlate the values of the UCS test with the results of the NDT …
the chromite mineral in the raw material in respect of kinetic reasons (retention time in smelting). 1. INTRODUCTION ... Th e factors studied were as follows: sintering temperature, compressive strength, degree of oxidation (e.g. sesqui oxide content), porosity (e.g. wood dust), coke powder addition and
The compressive strength of the solidified specimens in the control group reached a maximum value (99.21 MPa) after 10 freeze–thaw cycles, and a minimum value (86.91 MPa) after 50 freeze–thaw cycles. Moreover, the compressive strength of the solidified bodies after the other numbers of cycles did not change significantly (<4%).
The compressive strength of a magnesium chromite refractory in nitrogen was measured by rapidly loading specimens to failure at several temperatures up to 1600 O C. Strength retrogression was observed at temperatures above 1200°C. The creep behavior of the refractory in nitrogen was measured as a function of compressive stress in the range …
Download scientific diagram | Compression strength of pellets under wet and dried conditions. from publication: Binder Behavior on Chromite-Carbon Composite Pellets | The influence of binders on ...
Fig. 6 (a) shows the average pellet compressive strength under different carbon contents and reducing atmospheres. The results indicate that as the carbon …
The rock uniaxial compressive strength (UCS) has significant implications for underground engineering support design. Traditional methods mainly rely on laboratory tests, which are costly, time-consuming, and unable to meet the real-time adjustment of underground engineering support plans and construction safety requirements. To …
Chromite ore processing residue (COPR) is a hazardous waste because of leachable chromium, especially Cr(VI). Therefore, ascorbic acid (AA) and blast furnace slag (BFS) have been used to detoxify and solidify ... compressive strength development, and leaching concentration of Cr(VI). The result indicated that the
According to the optimal conditions of the single-factor experiment, the highest compressive strength of 147.6 MPa was obtained after using the water glass modulus 1.0, liquid–solid ratio 0.28, alkali–solid content 8%, curing temperature 45 °C. The COPR was solidified in the AACM sample having highest compressive strength.
This study has focused on reducing the carbon emissions and energy consumption for producing ferrochrome, an essential component in stainless-steel …
Typical Chromite Sand Testing • South African Chromite Sand is the world standard for metalcasting and foundry applications, however there can ... • Transverse tensile …
As the COPR content increased, the peak strength of the main crystalline phase magnesium chromite gradually increased, which may have led to incomplete dissolution of aluminosilicate, thus hindering the condensation reaction and leading to a decrease in compressive strength .
Chromite ore processing residue (COPR) is a typical hazardous waste, ... on compressive strength was investigated by single-factor experiment. Additionally, solidification effect of AACM was determined according to the compressive strength and the leaching concentration of chromium (Cr ...
The synthesize nano zerovalent iron by green tea (GT-NZVI). • Reduction of chromium existed in chromite ore processing residues (COPR) by GT-NZVI.. Significant results are achieved regarding compressive strength and Cr (VI) solidification.. Comparatively, GT-NZVI treated COPR has better solidification than untreated COPR.
compressive strength of concrete when chromium waste is used as admixture. In this respect, experimental factors at two levels, which are admixture type (chromite/ chromite+ superplastizer), admixture percentage (5-15%) and cure duration (7-28 days), are selected as possible candidates affecting the compressive strength.
This may be caused by the combined effect of magnetite core shrinking and possible particle deterioration at elevated temperatures due to the inferior thermal stability of magnetite spinel than chromite spinel, as can be revealed from Figures 11(a) and (b).[43–45] Then the compressive strength of preheated chromite pellet undergoes a …
Chromite ore processing residue (COPR) is a typical hazardous waste, which contains Cr(vi) and poses a great threat to the ecological environment and human health. ... According to the optimal conditions of the single-factor experiment, the highest compressive strength of 147.6 MPa was obtained after using the water glass modulus …