冬季施工对耐火浇注料的影响以及保温措施 The impact of winter construction on refractory castables and insulation measures

根据耐火浇注料的施工要求，为了保证浇筑质量，在冬季施工时必须采取保温措施防止浇注料及结合剂被冻坏。在冬季施工时，由于环境温度低，浇注料流动性较差，硬化时间较长，给施工带来一定困难。

According to the construction requirements of refractory castables, in order to ensure the quality of casting, insulation measures must be taken during winter construction to prevent the castable and binder from freezing. During winter construction, the low ambient temperature results in poor fluidity of the castable and a longer hardening time, posing certain difficulties for construction.

　以炉缸浇注料为例，低温浇筑对耐火浇注料的影响主要有以下几个方面：

　　一是施工温度过低，浇注料搅拌混合效果不好，出现搅拌不均匀的情况；

　　二是浇注料流动性变差，材料的气孔率增大，物理强度降低；

　　三是由于温度较低，硅溶胶结合反应缓慢，当温度低时，硅溶胶会出现冻胶，导致硅溶胶失效，进而影响浇注料的质量,在北方寒冷区域，会出现浇注料在施工时冻凝的现象，由于浇注料冻住，在解冻后强度会非常低，会出现分层掉块现象；

　　四是从凝结硬化上来说，由于温度低，硬化时间较长，影响施工进度。当温度在0℃以下时，不仅不能正常硬化，还会对材料内部结构产生不良影响，在烘炉时浇注体大面积脱落，影响正常投产。

　　根据上述高炉用耐火材料在冬季施工时，为了保证施工质量及浇注体强度，为了避免材料被冻坏，要求施工环境不能低于5℃，要采用一定的保温措施。通过现场施工技术指导实践，总结以下耐火浇注料冬季施工的保温措施.

Taking hearth castable as an example, the impact of low-temperature casting on refractory castables mainly includes the following aspects:

First, excessively low construction temperatures result in poor mixing of the castable, leading to uneven mixing.

Second, the fluidity of the castable deteriorates, the porosity increases, and the physical strength decreases.

Third, due to the low temperature, the silica sol bonding reaction is slow. At low temperatures, the silica sol may freeze, causing silica sol failure and affecting the quality of the castable. In cold northern regions, the castable may freeze during construction. Because the castable is frozen, its strength will be very low after thawing, resulting in delamination and spalling.

Fourth, in terms of setting and hardening, the low temperature results in a longer hardening time, affecting the construction progress. When the temperature is below 0℃, not only will normal hardening not occur, but it will also adversely affect the internal structure of the material, causing large-scale detachment of the castable during furnace drying, affecting normal production.

Based on the above, when constructing refractory materials for blast furnaces in winter, to ensure construction quality and the strength of the cast body, and to prevent the materials from freezing, the construction environment must not be lower than 5℃, and certain insulation measures must be taken. Through on-site construction technical guidance practice, the following insulation measures for winter construction of refractory castables are summarized.

措施一：

　　施工前用帆布或塑料膜将材料盖住，并且接入暖风机不断地进行保温处理，从而达到保温效果，值得注意的是，该方法必须保证防火安全，以避免引燃帆布或塑料膜。

　　措施二

　　施工时在搅拌机以及泵送机周围，布置暖棚以及接入一定数量的暖风机，提高搅拌机以及泵送机处的环境温度，合理规划电线线路，以不妨碍作业且放置安全为主。

Measure 1:

Before construction, cover the materials with tarpaulin or plastic film and continuously insulate them with a heater to achieve a heat preservation effect. It is important to note that this method must ensure fire safety to prevent the tarpaulin or plastic film from igniting.

Measure 2:

During construction, set up a heated enclosure and connect a number of heaters around the mixer and pump to increase the ambient temperature at the mixer and pump locations. Plan the electrical wiring reasonably, prioritizing safety and avoiding obstruction of operations.

                                                                                                                                      图为搅拌机及泵送机搭设暖棚

措施三：

 炉内施工时，在施工区域上方支设暖棚且在炉内接入暖风机，维持炉内温度，并且暖风机要合理安排风向，不能直接吹浇注体表面，防止局部温度过高导致浇注体开裂。

 措施四：

 对浇注用结合剂进行加热处理，温度控制在15℃-35℃为宜，需控制好加热温度防止温度过低或过热。

Measure 3:

During furnace construction, a heated shed should be erected above the construction area, and a warm air blower should be connected inside the furnace to maintain the furnace temperature. The blower should be positioned strategically to avoid directly blowing onto the surface of the casting, preventing localized overheating that could cause cracking.

Measure 4:

The bonding agent used for casting should be heat-treated, with the temperature controlled between 15℃ and 35℃. The heating temperature must be carefully controlled to prevent it from becoming too low or too high.