开水壶使用一段时间后,壶壁上会结上一层黄灰色或白色的沉淀物质,这就是我们常说的水垢。天然水中常含有硫酸钙和硫酸镁以及碳酸盐、硅酸盐等杂质,在加热后,所含杂质的结构改变,成为难溶于水的沉淀物而积聚起来,形成水垢。水垢对人体健康危害很大,因为它是一种十分复杂的物质,除盐类外,还含有大量的重金属成分,如镉、砷、汞、铅、铁 After using the kettle for a period of time, the wall of the kettle will be covered with a layer of yellowish-gray or white sediment, which is what we often say. Natural water often contain calcium sulfate and magnesium sulfate, as well as carbonate, silicate and other impurities, after heating, the impurities contained in the structure changes to become insoluble in water sediment accumulation, the formation of scale. Scale is very harmful to human health as it is a very complex substance that contains a large amount of heavy metals such as cadmium, arsenic, mercury, lead, iron