Chromite: The only mineral ore of chromium metal
Chromite is an oxide mineral composed of chromium, iron, and oxygen (FeCr 2 O 4 ). It is dark gray to black in color with a metallic to submetallic luster and a high specific gravity. It occurs in basic and ultrabasic igneous rocks and in the metamorphic and sedimentary rocks that are produced when chromite-bearing rocks are altered by heat or ...
Synthetic Solution for Cores & Molds? | Modern Casting
When comparing the index values for uncoated cores, penetration resistance was comparable to chromite sand, which can be attributed to the grain fineness value for bauxite and chromite. Silica sand performed the worst for coated and uncoated aggregate cores based on the overall index value, mainly due to a propensity to form veining defects.
REDUCING CORE DEFECTS
several different recipes of shell sand. Cold box can use new or reclaimed, or blend of both. Chromite or iron oxides can be added during the sand preparation. Sand grain finest can be a fine grain silica for smooth lacy cores or lake sand for a more rugged, porous core. Depending on your process, you will require some type of curing methodology to
Laboratory Services | Minerals Technologies Inc.
The Acid Demand Value is the amount of acid required to bring high pH and total alkalinity down to their proper levels. This gives insight to carbonates and salts in silica sand. A high acid demand value can lead to pinhole defects in castings due to the production of CO2 gas and lower the life of foundry sands in cold box systems.
Design and Development of Knowledge Base Scheme for Chromite …
An expert system is developed in the present paper to predict the mechanical properties of chromite-based resin bonded sand core system. The various properties of sand cores, such as hardness, compression strength, collapsibility, tensile strength, hot strength, shear strength and permeability depends upon numerous process parameters, …
Influence the Composition of the Core Mixture to the Occurrence …
cold-box-amin technology from Si sand T+T and surface of castings produced of these cores. Pic.3 Cores RC 56048/1 produced by cold-box-amin technology, composition of injection mixture: 100 kg Si ...
Analysis of Chemically Bonded Sand Used for Molding in Foundry
There are several types of molding methods, but over 70% of all metal castings are generally developed by means of sand molding (sand casting). Sand casting has two processes such as, green sand ...
Spherical Ceramic Sand for Foundry Naigai CERABEADS 60
Anti-Burn-on (Good alternative to Zircon and Chromite sand) Applications CERABEADS Chromite, etc Heat by Molten Metal Still Easy to be Shaken out Burnt Layer Molten Metal Difficult to be Shaken out ... Process Mold: Green Sand Core: Cold Box (with paint) Effect of CERABEADS High dimensional accuracy Thickness (Wall of Product): 3 mm
Sintered ceramic sand for foundry with cold core box
The cold box method refers to a resin sand forming process that is catalyzed/hardened by blowing in gas or aerosol, and formed instantaneously at room temperature. The common method is the triethylamine method, which uses phenolic-urethane resin and is hardened by blowing triethylamine gas. The characteristics of this process are: the core sand ...
High-quality manufacturing method of complicated castings
A multi-material hybrid patternless moulding process for complicated castings has been proposed. Moulding sands used in the hybrid moulding process include silica sand, ceramic sand, chromite sand, zircon sand, and steel shot sand. Experimental method was used to study the effects of moulding sands on the temperature field, …
Control of the Strength Properties of Mixtures Based on Chromite Sand
The compositions of cold-hardening mixtures on chromite sand were optimized, allowing obtaining high-quality cores with high strength properties. It has been established that FOPCC is a material that has a double effect; it hardens the mixture during preparation and softens it after pouring metal during decoring. ... In the CO 2 process, …
Experimental Studies on Properties of Chromite-based Resin …
Key-Words: - Chromite sand, central composite design of experiments, compression strength, permeability. 1 Introduction . With the rapid developments in foundry industry, variety of resin bonded sand systems has been introduced for mould and core making. These systems are called cold-box process, as the mould/core is allowed to cure at the …
USE OF COLD BOX PROCESS
USE OF COLD BOX PROCESS INTRODUCTION Cold Box Process Over a last decade considerable improvements in the core making process have been made ... Cold Box …
Chill Casting,Chill Casting Process,Applications of Chill Casting
Other sand materials with higher densities, thermal conductivity or thermal capacity can also be used as a chill. For example, chromite sand or zircon sand can be used when molding with silica sand. The process employs chill-casting techniques and a specialty-steel mold to produce precision castings made from copper and copper-base alloys.
Study to improve the breaking strength of the no-bake …
The Hevi chromite sand produced by a single stage washing of chromite sand was found to exhibit lower breaking strength in service. ... box, cold box, shell process, no-bake, clay . and baking ...
Application of Response Surface Methodology for Modeling …
Sand – Chromite Sand . Sand is the major ingredient i.e. about 95 to 98% of the total moulding/core sand mixture consists of sand. Hence, the type and characteristics of sand play major role in developing the important properties. Chromite sand is dense, weighing 160 lbs per cubic feet compared to silica sand (weighing 98 lbs per
Study to improve the breaking strength of the no-bake chromite sand
It is defined as the time from when box, cold box, shell process, no-bake, clay the furan resin was first added to chromite and baking binders such as core oil. The no- sand + furan acid catalyst mixture to the time bake process is a major technique in use in when the WT/ST) pad reaches a "B" scale foundries.
Effect of binder and moisture content on compactibility and shear
1. Introduction. Green sand mould casting process is one of the popular casting processes to produce ferrous and non-ferrous castings. The raw material of sand mould is easily available and reusable hence, 70% casting is being manufactured by sand casting process [1].The sand mould has good permeability, hardness and strength …
Chromitite layers indicate the existence of large, long-lived, and
The separation of touching chromite crystals in 3D was done using a modified version of the algorithm used to separate touching chromite in komatiites 89 and chromite from the normal Merensky Reef ...
Assessment of local chromite sand as 'green' refractory raw …
The sample size was made of two types of local foundry sands: silica sand and chromite sand. These samples were donated by two local foundry sand suppliers. An amount of 1100g of each sample was collected for testing. 2.3 Sand characterisation. The following tests were performed on the sand samples: - chemical analysis - sieve analysis
Chrome Sand | Refractory Application | African Pegmatite
Sand. Refractory Application. Chrome sand is used in the production of chrome magnesite refractory bricks, which are used in the construction of certain furnaces and kilns. Due to its highly corrosion-resistant nature, chrome sand is also used to produce magnesia chrome refractories that are used in non-ferrous metals like copper, lead, and zinc.
Gas-Hardened Processes (Cold-Box) | SpringerLink
A molding sand hardening in these processes occurs as a result of the influence of a catalyst or hardener, in a gaseous form, on components of binding …
Cold Box Casting Process
These essentially represent silica sand, chromite sand and zircon sand. Working with the cold box process requires resin, activators, catalyst and refractory matix components. Coreboxes for the cold box process may …
Heat Curing Processes | SpringerLink
The special advantage of the warm-box technology is a low emission of gases during the core storing (app. 5–10 times smaller than in the cold-box process) and casting producing. As an example, at a temperature of 800 °C, the emission of substances from the BTEX group from molding sands obtained in the warm-box technology is a few …
Sunday GunDay — How to Fill Sandbags & Fill Material Options
Chromite typically sells for about 25-30% less than Zircon (comparing bulk prices of both types of sand). Chromite sand is black in color. So when you buy "heavy sand," make sure you are getting what you pay for. 1.00 pound of Chromite displaces 152cc vs. 295cc for Play Sand. So, that means Chromite is 94% heavier than an equal volume …
Cold box process
Process for the production of cores in which, in principle, cold, i.e. not heated or hot, core boxes are used. The popularity of this process (it has now been in existence for over 40 years) and, above all, the possibility of creating core shapes with high productivity lead to it having a market share of more than 60% ( Fig. 1, ASK Chemicals ).
Green Sands | SpringerLink
An excess of lustrous carbon in a molding sand, especially when it is together with a core sand originated from burned cores made in the cold-box technology with using amines, can be the reason of a defect called "elephant skin" . At large amounts of lustrous carbon, its layers can separate themselves from the mold surface and be caught …
Effect of Cr2O3 Addition on Sintering Behavior of Novel Chromite…
SiO 2 is crucial for forming the liquid phase during the sintering process. The SiO 2 content of the sand should be about 20% to achieve optimal sintering effects. Chromite sand for casting is not suitable for the steels.
Comparing Sands From Different Reclamation Processes for Use …
The use of reclaimed sands in the cold-box core room is discussed, comparing three different reclamation processes. The first is called a thermal process …
Cold-box process for preparing foundry shapes
The invention relates to a cold-box process for preparing foundry shapes. The process involves curing a foundry shape by subjecting it to carbon dioxide and heat. ... Other suitable sand includes zircon, olivine, alumina-silicate sand, chromite sand, and the like. Generally, the particle size of the sand is such that at least 80 percent by ...