Chromium
Yield strength or yield stress is the material property defined as the stress at which a material begins to deform plastically whereas yield point is the point where nonlinear (elastic + plastic) deformation begins. See also: …
Minerals | Free Full-Text | An Overview of Currently …
Chromite briquettes have lower compressive strengths and lower Cr recovery during smelting when compared to sintered/pre-reduced pelletized chromite . …
Compressive Strength and Creep Behavior of a Magnesium Chromite …
The compressive strength of a magnesium chromite refractory in nitrogen was measured by rapidly loading specimens to failure at several temperatures up to 1600OC. Strength retrogression was ...
Research on the environmental stability performance of chromite …
Chromite ore processing residue (COPR) is a hazardous waste because of leachable chromium, ... However, in the freeze–thaw cycle experiments, the compressive strength of the solidified bodies consistently remained above 80 MPa, and the leaching of hexavalent chromium was below the limit (5 mg L −1). In addition, X-ray diffraction (XRD) …
Research on the environmental stability performance …
Specifically, the compressive strength of the solidified body was higher than 100 MPa when the addition of COPR was less than 30%. When the COPR content increased to …
Utilisation of pre-oxidised ore in the pelletised chromite pre
In Fig. 7 A, the compressive strengths of pre-reduced pellets produced from chromite ore that were pre-oxidised at different temperatures are compared with the breaking strength of pre-reduced pellets made from un-oxidised chromite ore (base case, indicated with dotted line). It is evident from the results that the pre-reduced pellets made …
v115n8a6 Comparison of physical properties of oxidative …
produced with conventional South African metallurgical-grade chromite ore (from the Lower Group 6 or the Middle Group 1 and 2 seams). A statistical evaluation of the cured (sintered) compressive strengths proved that pellets prepared from UG2 ore are likely to have the same, or better, compressive strength than pellets prepared from ...
Research on the environmental stability performance of chromite …
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 strength of the ...
(PDF) Sodium Silicate Cold-Bonded Chromite …
It was determined that pellets cured at 75 °C had compressive strengths of 2.41-3.12 kN. The mechanical strength of these cold-bonded pellets where similar to, or exceed that of pellets currently ...
Chromite Ore
Chromite is an end member of a complete solid solution series between naturally occurring chromites contain iron and magnesium as substituting impurities with chromium oxide. ... However, the compressive strength achieved with FCS as a binder in geopolymer is very low, and thus more studies are needed to establish the possibility of strength ...
Solidification/stabilization of chromite ore processing
The compressive strength is determined by using universal testing equipment (AGN-250, Shimadzu, Japan) to test the average value of three parallel samples. Corrosion resistance test The corrosion resistance test is conducted with reference fine ceramics-determination of corrosion resistance of monolithic ceramics in acid and …
Value-added utilization of waste silica powder into high …
The influence of chromite with different Cr/Fe ratios on compressive strength of preheated and roasted pellets is described in Fig. 4. When increasing the Cr/Fe ratio from 1.35 to 2.55, the strength of preheated and roasted pellets was obviously reduced from 506 N/P and 1900 N/P to 190 N/P and 690 N/P, respectively.
Study the effect of chromite ore properties on
Chromite ore fines (0–25 mm) are commonly used to produce sintered pellets to use in ferrochrome production process. In the chrome ore pelletisation process chromite ore along with 4–5% coke is milled in the wet ball mill and filtered ore cake is mixed with bentonite and used for production of green pellets. ... The compressive …
Insight into the Consolidation Mechanism of Oxidized Pellets …
Effect of mass proportion of chromite concentrates on the compressive strength of the fired pellets. Conditions of raw materials: MP-no pretreatment; CMP-1, CMP-2, CP-HPGR pretreatment, the SSA value of pellet feeds are 1800–1900 cm 2 /g. All fired pellets were manufactured by preheating at 1323 K (1050 °C) for 9 min and firing at …
Hydrogen-based pre-reduction of chromite: …
Based on the findings in Fig. 5, the compressive strength decreases with higher Fe metallization, possibly due to the reduced binder quantity and the oversized metal Fe grains. These factors could result in cracks between the metal Fe and …
Control of the Strength Properties of Mixtures Based …
According to the process sample, the compressive strength of chromite mixture is an average of 1,5 MPa after 1 h; 2,5 MPa after 3 h; 3,5 MPa after 24 h. The …
Ferrochrome slag: A critical review of its properties, …
Ferrochrome slag (FCS) is a by-product of ferrochrome industries and is produced during the extraction of ferrochrome from chromite ore. The chemical composition of FCS comprises of 27–33% SiO 2, 15–25% Al 2 O 3, 20–35% MgO, and 10–15% iron-chromium compounds.The high chromium content of FCS and the …
Preparation of Oxidized Pellets with Chrome Ore
Compressive strength of preheated pellets increased from 288.44 to 515.32 N/P when the temperature is increased from 1000 to 1100 °C. The above study …
IJERPH | Free Full-Text | The Utilization of Alkali-Activated
Additionally, compressive strength and leaching toxicity were the indexes used to evaluate the performance of the solidified bodies containing COPR. As a result, the highest compressive strength of alkali-activated LZSS reached 84.49 MPa, and when 40% COPR was added, the strength decreased to 1.42 MPa.
Immobilization of chromite ore processing residue with
Based on the compressive strength, the optimum conditions for preparing blast furnace slag-based geopolymer (SG) were BFS/solid of 90 wt%, a water glass/NaOH mass ratio of 7:3, a liquid-to-solid ratio of 0.25, and a BFS grinding time of 12 h. The 28-day compressive strength of the geopolymer was 50.4 MPa. Chromite ore processing …
Recycling Of Chromite Waste for Concrete: Full Factorial Design
The compressive strength test, split tensile strength test, and flexural strength test were conducted and compared with conventional concrete for 7- and 28-days curing, study's results showed an ...
What is Compressive Strength?- Definition, Formula
Compressive strength refers to the ability of a certain material or structural element to withstand loads that reduce the size of that material, or structural element when applied. A force is applied to the top and bottom of a test sample, until the sample fractures or is deformed. Materials such as concrete and rock are often evaluated using a ...
Solidification/stabilization of chromite ore processing …
The compressive strength of all the specimens at 7 days of curing was higher than the 350 kPa recommended by the USEPA regulation (USEPA, 1986), and the compressive strength at 28 days of curing ...
Minerals | Free Full-Text | An Overview of …
Chromite briquettes have lower compressive strengths and lower Cr recovery during smelting when compared to sintered/pre-reduced pelletized chromite . Thus, only pelletization processes were …
Research on the environmental stability performance of chromite …
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 …
FACTORS AFFECTING THE REDUCIBILITY OF SINTERED …
executed by stopping the pellet cooling at 1100°C for 60 minutes. The temperatures needed for a compressive strength of 100 kp respectively of 200 kp varied dependi ng on the pelletizing mixture. This also affected the oxidation of chromite iron [4]. This phase of the study included 24 sintering cases.
An Assessment of South African Chromite Sand Crushing Ratio
[Show full abstract] are likely to have the same, or better, compressive strength than pellets prepared from metallurgical-grade chromite ore. The cured abrasion strength of the UG2 pellets was ...
Comparison of physical properties of oxidative sintered
A statistical evaluation of the cured (sintered) compressive strengths proved that pellets prepared from UG2 ore are likely to have the same, or better, compressive strength than pellets prepared from metallurgical-grade chromite ore. The cured abrasion strength of the UG2 pellets was also superior to that of the metallurgical-grade pellets.
Detoxification and immobilization of chromite ore …
Modulus refers to the mole ratio of SiO 2 and Na 2 O in the alkali activators (water glass and sodium hydroxide). The compressive strength increased with increment of modulus up to a certain value, and further increase caused the decline in strength which could be seen in Fig. 1 (a).Highest compressive strength of 112.92 MPa was observed …
Pelletization of a Low-Grade Indian Chromite Overburden
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.
