輕燒鎂粉是一種重要的耐火材料 Light burned magnesium powder is an important refractory material

輕燒鎂粉是一種重要的耐火材料

輕燒氧化鎂粉是一種具有中等堿度和化學活性的原料，除作為耐火材料和膠凝材料外，還應用于其他工業領域。另外，轉爐濺渣護爐技術的發展，進一步擴展了輕燒氧化鎂粉的應用范圍。目前，濺渣護爐技術多將輕燒氧化鎂粉成球后使用，有輕燒氧化鎂粉球、含碳輕燒氧化鎂分球和含碳含鈣輕燒氧化鎂粉球等。

輕燒氧化鎂粉，簡稱輕燒鎂粉，是一種由菱鎂礦、水鎂石和由海水或鹵水中提取的氫氧化鎂經800~1000℃左右煅燒所獲得活性氧化鎂。輕燒鎂粉為呈淡黃色、淡褐色的粉末，粒度大都在100目以下，方鎂石結晶很小，密度3.07~3.22g/cm3,晶格常數大，晶格缺陷多，質地松脆，呈多孔結構，反應活性很大，易進行固相反應或燒結，與水作用生成Mg(OH)2而硬化，有粘結能力。

選擇煅燒方式及控制輕燒溫度是獲得良好活性的重要手段。隨著煅燒溫度的提高，MgO的比表面積顯著下降。當溫度大于1000℃時，MgO重結晶速度加快，分散度急劇下降，活性變差。在相同的溫度下采用不同的煅燒方式和煅燒設備也是影響MgO活性的重要因素。如采用沸騰爐、懸浮爐煅燒，使其在瞬間迅速分解，可獲得具有最大活性的輕燒氧化鎂粉。采用隧道窯、反射窯大塊的方式，煅燒時間長，往往會使表面過燒而內部生燒，都將使輕燒氧化鎂粉的活性降低。采用回轉窯煅燒粒狀菱鎂石，情況介于兩者之間，也能使獲得輕燒氧化鎂粉保持較好的活性。

1 成品每批的重量不大于 120 t 。

2 測定粒度的樣品應在組批前進行采樣,化學分析的樣品應在組批后進行采樣。小袋 (25kg) 每 20 袋取一個份樣,每個大袋 (1000kg)取一個份樣。

將取得的粒度樣品充分混勻后,點取 10~20g 測定粒度?；靹蚝蟮幕灅悠房s分為 200g 送化驗室進行分析。

3 檢驗結果如有某項化學成分不合格或異常,則在同一批產品批量中重新取雙倍數量的樣品進行復驗一次,以復驗結果為該批產品的最終檢驗結果。

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.