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Why Reclaim?


There is a sand reclamation plant to suit every metalcasting facility’s requirement and budget.


CHRIS WILDING, OMEGA FOUNDRY MACHINERY LTD. 为何再生


现代砂再生工厂进化出这样一种方式,即使是最小的可容纳铸造的建筑面积的工 厂,但在投资和运行费用方面,从本质上讲是一个的砂回收厂,以适应每个铸造 厂的需求和预算。


chris wilding, omega foundry machinery ltd. T


oday’s metalcasting facility using one of the many chemically bonded sand systems is under increas- ing pressure to reduce costs and its impact on the environment while improving and maintaining


its casting quality. One way to meet these requirements is to invest in sand reclamation. Cost reductions after installing a sand reclamation system


are made by reusing the sand after casting, buying less new sand and, with some systems, reducing the binder content at the mixer. Tere is an obvious reduction to the impact on the envi-


ronment from dumping less sand. Casting quality is improved by using less resin at the


mixer and improving the sand grain’s characteristics so it becomes more rounded. A more rounded sand grain leads to better compaction after mixing, greater strength and better surface finish.


Reclamation Requirements To reclaim the sand, the equipment first must reduce the


lumps back to grain size, remove all coarse and agglomerated sand grains as well as dust and fine particles. Te sand must be cooled before reuse but, more importantly, as much binder must be removed as possible.


Characteristics of the Sand


After reclamation, the shape of the grain changes due to the attrition part of the process, where sand grains rub together. The effect is that all sharp edges are removed and extracted from the sand as dust. It also is impor- tant that the AFS or average grain size does not change dramatically from the new sand that was first used. The type of reclamation must not be too harsh or damaging to the sand grain. The silica content of the sand should be as high as possible and the acid demand value (ADV)


来越大的降低成本压力,减少对环境的影 响,但同时改善和维持它的铸造品质量。满足这些要 求的有效方法之一是增加在旧砂再生设备投入。 安装旧砂再生装备后的运行成本实际上是降低后重 新使用的砂铸造后,购买新砂少,在某些混砂系统中 的粘结剂的含添加量在混砂实际上是减少的。 由于较少的砂被排放,有一个明显的减少对环境的


当 影响。


在混砂系统中器,通过使用更少的树脂和改善砂粒 的特性,铸件质量因砂粒变得更圆整而提高。因为一 个更圆的沙粒混合后,得到更大的强度和更好的表面 光洁度。


再生要求


砂再生所使用的设备必须首先破碎砂块变回砂粒, 去除所有粗包覆砂粒表面的粘结剂膜,灰尘和细粉及 砂团。沙子在重新使用之前必须被经冷却,但更重要 的是,和尽可能多的除去粘结剂。


砂子特性


再生后的砂粒形状改变因为磨擦过程中砂粒相互 碰撞。所有尖锐的边缘被磨掉,并从中变成灰尘被 中风选出砂子。同样重要的是,从新砂第一次被使用 起,AFS或平均砂粒尺寸不发生显着变化,。因此, 重要的是,再生的类型不能太粗糙或破坏砂粒形状。


32 | FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION February 2013 今的铸造业使用化学粘结剂砂,在越


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