NEWS
In the foundry industry, the use of natural sodium bentonite
Release time:
2024-05-24
Bentonite is also called parthenolite, bentonite or bentonite. The development and use of bentonite in China has a long history. It was originally only used as a detergent (there were open-pit mines in Renshou area of Sichuan Province hundreds of years ago, and local people called bentonite as soil powder). It has been widely used for only a hundred years. The United States was first found in the ancient strata of Wyoming, a yellow-green clay, which can expand into a paste after adding water. Later, people referred to all clays with this nature as bentonite.
Bentonite for casting is one of the largest "users" of bentonite. Bentonite for casting mainly includes sodium bentonite and calcium sodium bentonite. Sodium-based bentonite is made from natural sodium-based bentonite or artificial sodium-based bentonite, which is welcomed by the foundry industry for its good reusability and high wet pressure strength. Because of its good plasticity, it can prevent casting sand, scarring, falling blocks, sand collapse and other phenomena. In addition, it has strong formability and high cavity strength, which is convenient for metal industry to cast wet or dry molds. It is the preferred sand binder for precision castings. The calcium sodium bentonite is processed by the natural base calcium sodium bentonite, is the light casting commonly used sand binder, it is practical and casting sand cleaning convenient and welcomed by users.
Bentonite is used in the foundry industry, in order to make the processing of castings better performance, bentonite consistency is usually a key factor. Not paying attention to bentonite consistency will only produce high-cost and low-quality castings. Therefore, many foundries, especially those using mechanized production lines, attach great importance to the consistency of the bentonite used.
(1) All kinds of bentonite, including natural sodium bentonite, natural calcium bentonite and artificially activated sodium bentonite, have relatively low solid/semi-solid boundaries, and there is little difference between all kinds of bentonite. In order to make clay wet sand obtain higher wet compressive strength with lower moisture, the solid/semi-solid boundaries of bentonite are of course lower.
(2) After analyzing the active bentonite content and moisture content of the commonly used clay wet sand, we can know that the soil-water system in the clay wet sand is a semi-solid paste. Moreover, whether natural sodium soil, artificially activated sodium soil, or calcium soil is used, the difference between the solid/semi-solid boundary and the semi-solid/plastic boundary is not too large. Therefore, no matter what kind of bentonite is used, the ratio between soil/water in the sand will not be much different.
(3) The difference between the semi-solid/plastic boundaries of various bentonites is relatively small, and its effect on the performance of the sand is very small. The ratio of moisture and active bentonite content in clay wet sand generally does not exceed this limit.
(4) The difference between various bentonites is very large, and the plastic/liquid boundary of natural sodium soil can be 3.5 to 6 times that of natural calcium soil. In order to avoid reducing the mold wall movement of the sand mold after pouring, it is hoped that the water coacervate formed close to the mold surface after pouring will have higher strength and can absorb more water before turning into liquid. For this purpose, it is of course required that the plastic/liquid limit of the bentonite is as high as possible, and in this respect the weakness of calcium bentonite is very obvious.
Contact Us
Address: Wuying Zi Village, Shahai Town, Jianping County, Chaoyang City, Liaoning Province
Telephone:+86-15084222222
+86-18618376678 +86-13310388567
E-mail:huihenghe@163.com
龙腾矿业
WeChat Public Number
Copyright©2024 Jianping Longteng Mining Co., Ltd.