轻烧镁粉是一种重要的耐火材料 Light burned magnesium powder is an important refractory material

轻烧镁粉是一种重要的耐火材料

轻烧氧化镁粉是一种具有中等碱度和化学活性的原料，除作为耐火材料和胶凝材料外，还应用于其他工业领域。另外，转炉溅渣护炉技术的发展，进一步扩展了轻烧氧化镁粉的应用范围。目前，溅渣护炉技术多将轻烧氧化镁粉成球后使用，有轻烧氧化镁粉球、含碳轻烧氧化镁分球和含碳含钙轻烧氧化镁粉球等。

轻烧氧化镁粉，简称轻烧镁粉，是一种由菱镁矿、水镁石和由海水或卤水中提取的氢氧化镁经800~1000℃左右煅烧所获得活性氧化镁。轻烧镁粉为呈淡黄色、淡褐色的粉末，粒度大都在100目以下，方镁石结晶很小，密度3.07~3.22g/cm3,晶格常数大，晶格缺陷多，质地松脆，呈多孔结构，反应活性很大，易进行固相反应或烧结，与水作用生成Mg(OH)2而硬化，有粘结能力。

选择煅烧方式及控制轻烧温度是获得良好活性的重要手段。随着煅烧温度的提高，MgO的比表面积显著下降。当温度大于1000℃时，MgO重结晶速度加快，分散度急剧下降，活性变差。在相同的温度下采用不同的煅烧方式和煅烧设备也是影响MgO活性的重要因素。如采用沸腾炉、悬浮炉煅烧，使其在瞬间迅速分解，可获得具有最大活性的轻烧氧化镁粉。采用隧道窑、反射窑大块的方式，煅烧时间长，往往会使表面过烧而内部生烧，都将使轻烧氧化镁粉的活性降低。采用回转窑煅烧粒状菱镁石，情况介于两者之间，也能使获得轻烧氧化镁粉保持较好的活性。

1 成品每批的重量不大于 120 t 。

2 测定粒度的样品应在组批前进行采样,化学分析的样品应在组批后进行采样。小袋 (25kg) 每 20 袋取一个份样,每个大袋 (1000kg)取一个份样。

将取得的粒度样品充分混匀后,点取 10~20g 测定粒度。混匀后的化验样品缩分为 200g 送化验室进行分析。

3 检验结果如有某项化学成分不合格或异常,则在同一批产品批量中重新取双倍数量的样品进行复验一次,以复验结果为该批产品的最终检验结果。

Light burned magnesium powder is an important refractory material

Light-burned magnesia powder is a raw material with medium alkalinity and chemical activity. In addition to being used as refractories and gelling materials, it is also used in other industrial fields. In addition, the development of converter slag splashing furnace protection technology has further expanded the scope of application of light-burned magnesia powder. At present, slag-spattering furnace protection technology mostly uses light-burned magnesia powder into balls, including light-burned magnesia powder balls, carbon-containing light-burned magnesia balls and carbon-containing calcium-containing light-burned magnesia powder balls.

Light-burned magnesia powder, referred to as light-burned magnesia powder, is a kind of activated magnesium oxide obtained by calcining magnesite, brucite and magnesium hydroxide extracted from seawater or brine to about 800 ~ 1000 ℃. Light-burned magnesium powder is a light yellow and light brown powder with a particle size of less than 100 mesh. The periclase crystals are very small with a density of 3.07 ~ 3.22g / cm3, a large lattice constant, many lattice defects, and a crisp texture. It has a porous structure and is highly reactive. It is easy to undergo solid phase reaction or sintering. It reacts with water to form Mg (OH) 2 and hardens. It has binding ability.

Selecting the calcination method and controlling the light firing temperature are important means to obtain good activity. With the increase of calcination temperature, the specific surface area of MgO decreased significantly. When the temperature is higher than 1000 ° C, the recrystallization speed of MgO increases, the degree of dispersion decreases sharply, and the activity deteriorates. Using different calcination methods and calcining equipment at the same temperature is also an important factor affecting MgO activity. If it is calcined by a boiling furnace or a suspension furnace, it can be quickly and rapidly decomposed to obtain light-burned magnesia powder with maximum activity. By adopting the block method of tunnel kiln and reflection kiln, the calcination time is long, and the surface is often over-burned and the internal burn-in is caused, which will reduce the activity of light-burned magnesium oxide powder. Rotary kiln is used for calcining granular magnesite, the situation lies between the two, and it can also keep the activity of obtaining lightly burned magnesia powder.

1 The weight of each batch of the finished product is not more than 120 t.

2 Samples for determination of particle size should be sampled before the batch, and samples for chemical analysis should be sampled after the batch. Small bags (25kg) take one sample every 20 bags and one large bag (1000kg) take one sample.

After the obtained particle size sample is thoroughly mixed, 10 to 20 g is taken to determine the particle size. The mixed test sample is divided into 200g and sent to the laboratory for analysis.

3 Inspection results If any chemical composition is unqualified or abnormal, double the number of samples in the same batch of product for re-inspection once, and the re-inspection result is the final inspection result of the batch of products.