acid demand and strength on chromite sand

Voxeljet VX 1000. The optimum catalyst addition ranged between 0.3 and 0.6% yielding to transverse strength in the ... chromite sand, olivine sand, synthetic sand [1]. ... pH level, acid demand, refractoriness, surface morphology and angularity of local sands on the mechanical properties ...

8.4 Acid Demand Value 8.4.1 Stir together for at least 5 minutes, 50 grams of chromite sand, 50 ml of distilled water and 50 ml of N/10 HCl. 8.4.2 Allow to stand for a minimum period of 1

Study to improve the breaking strength of the no-bake chromite sand-furan resin cores. ... sand + furan acid catalyst mixture to the time . ... acid demand value and . moisture content. In this ...

The sand coating consisted of addition sulfonic acid to 50 kg of silica sand in a foundry batch sand mixer. The sulfonic acid addition was determined at 0.3, 0.6 and 0.9% per weight of the sand. The mixing time was maintained constant at 5 minutes per batch of sand. The

Acid Demand Value (ADV) of Sand. In this module, the AFS 1114-00-S: Acid Demand Value (ADV) of Sand test will be demonstrated. Module topics will include: purpose of the ADV test, basic variables that factor into the test, and performing the test in a virtual environment. By the end of this module, you will be capable of measuring the Acid ...

The expansion of Silica Sand is compared below against the popular "Special Refractory Sands" such as Chromite and Zircon. IMPURITIES CONTAMINATES AND TESTING PROCEDURES The Acid Demand Value test: The acid demand value is important because it displays the amount of alkaline materials that should not be present in washed and classified ...

Sand is an excellent thermal insulator, so it transfers heat at a ... silica, olivine and chromite. The newly created, less angular grains have a reduced surface area that requires less binder. ... increases the binder's strength unless, of course, it becomes so not that resin burns up. The postcure of the oil urethane resin coating

• pH and Acid Demand Value - important tests in predicting issues with curing and strength development in chemical binder systems • LOI- Loss on Ignition - can be used to look for accessory minerals and impurities associated with the chromite sand. • Turbidity- an indicator of the cleanliness of the chromite sand

humidity, turbidity, acid demand value and moisture content. In this study, a cost effective method to improve the breaking strength of shapes and cores from foundry mixes consisting of Hevi chromite sand, furan resin and catalyst was investigated. 2. Experimental 2.1. Materials About 20 kg of chromite ore sand …

Feb 01, 2017· Feb 01, 2017· Q: Our foundry runs pH and Acid Demand Value (ADV) tests on our mold and core sands. Both of these tests measure the acidity or basicity of the sands. Why do we run both tests? A: Both pH and ADV are related to the acidity and basicity of the sand. When we consider the most common type of foundry sand, that is silica sand, both tests are related to the impurities normally found in the sand.

15.2.2 Chromite Sand. Chromite is a widely used aggregate valued for its relatively low thermal expansion and good chilling power, particularly for steel castings. However, the general problem with chromite is only found in steel casting operations where it is commonly employed as a facing sand …

and casting performance of silica and chromite sand. This product was created by Curimbaba Group and has the name of CastBall. The following physical properties were evaluated for each sand sample; AFS-GFN, tensile profiles, specific surface area, pH, acid demand value (ADV),

Aug 31, 2020· Aug 31, 2020· Keywords: chromite foundry sand; ophiolite chromite; acid demand test; silicate mineralogy 1. Introduction Chromite foundry sands, bonded with resins, are employed in the industry to form molds for casting metal and steel when high performance of sand is required (Figure1A,B) [1]. They have special

Besides strength variation, sand segregation often changes the catalyst requirements since the chemistry of smaller particles, which have the greatest effect on acid demand value, generally varies dramatically from that of the larger ones.

Chromite foundry sands must meet strict quality parameters, referred to as Cr2O3 content, Fineness Index, SiO2 content, and Acid Demand. The foundry chromite market is dominated by South Africa ...

The acid demand value (ADV) depends on the chemical composition of the sand. A catalyst requirement of cold-setting, acid catalyzed binders is selected as per ADV. If sands has ADV about 6-10 ml, it requires large quantity of acid catalyst and sand with ADV greater than10–15 ml are not acceptable for acid catalysed binder systems.

sand, 50 ml of distilled water and 50 ml of @l N hydrochloric acid. Allow to stand for a minimum period of 1 hour and back-titrate the resulting solution with 0.1 N sodium hydroxide solution topH 3,4 and 5. The amount of acid consumed at each pH level gives the acid demand value of the sand.