烧结砖裂纹原因及防治办法

Causes of Cracks in Sintered Bricks and Prevention Measures

原料原因造成的产品裂纹

Product Cracks Caused by Raw Material

一、原料本身特性造成的产品裂纹

I. Product Cracks Caused by the Characteristics of Raw Materials

1、干敏系数过高

1. Excessive Dry Sensitivity Coefficient

干燥敏感性系数用来衡量产品裂纹倾向性的大小，干敏系数越高，产品形成裂纹的倾向性越大，反之越小。当干敏系数大于2时，裂纹几乎不可避免；当干敏系数小于1时，产品一般不易形成裂纹。

The drying sensitivity coefficient is used to measure the crack tendency of products. The higher the drying sensitivity coefficient, the greater the crack tendency of products, and vice versa. When the dry sensitivity coefficient is greater than 2, cracks are almost inevitable; when the dry sensitivity coefficient is less than 1, cracks are not easy to form.

这种类型的裂纹在一些黏土砖厂和一些黏土掺量高的砖厂最为常见。

This type of crack is most common in some clay brick factories and some brick factories with high clay content.

防治措施：

Prevention and control measures:

a 、建厂前必须事先对准备使用的原料进行化验，慎用干敏系数高的原料。

A. The raw materials for preparation must be tested beforehand before the plant is built, and the raw materials with high dry sensitivity coefficient must be carefully used.

b、适量掺加瘠化剂，炉渣、煤矸石、粉煤灰、铁矿渣等都是很好的瘠化剂。

B. Adding proper amount of barrenizer, slag, coal gangue, fly ash, iron ore slag and so on are good barrenizers.

2、塑性太差

2. Too poor plasticity

原料塑性太差会造成成型困难，成型时裂纹严重，即便勉强成型，因坯体质量差、机械强度低，抵抗裂纹的能力就差，在干燥、焙烧过程中就容易产生裂纹。这种情况就好比有的人身体素质差，一遇天气变冷就容易感冒，而身体素质好的人抵抗气温变化的能力强，遇冷就不容易感冒。

Too poor plasticity of raw materials will lead to forming difficulties. Cracks are serious during forming. Even if the billet is formed reluctantly, the ability to resist cracks is poor because of poor quality and low mechanicatongzhongg.75ix.cnguolvwang.jk56.orgjiankongm.jk56.org bilieqii.jk56.org ronguanqiz.jk56.org lixinbeng.75ix.coml strength of the billet. Cracks are easy to occur during drying and roasting. This situation is like some people's poor physical quality, when the weather becomes cold, they are easy to catch a cold, while people with good physical quality have a strong ability to resist temperature changes, and when cold, they are not easy to catch a cold.

防治措施：

Prevention and control measures:

a、砂性黏土可掺加增塑剂，如膨润土、高塑性黏土、造纸黑液等。

A. Sandy clay can be mixed with plasticizers, such as bentonite, high plastic clay, black liquor of paper making, etc.

b、煤矸石、页岩等可降低其粒度增加塑性，也可采用掺加增塑剂的方法。

B. Coal gangue and shale can reduce the grain size and increase plasticity, and plasticizer can also be added.

3、泥料的颗粒级配不合理

3. unreasonable particle size distribution of sludge

所谓颗粒级配，即指泥料中各种粒径颗粒所占的比例。一般要求有三种粒径：细粉料（也称塑性颗粒，0.053㎜以下），填充性颗粒（0.053-1.2㎜），粗骨料（饰纹性颗粒，1.2-2.4㎜）。细粉料的含量决定了泥料的塑性，一般应占35-50%；填充性颗粒应占20-65%，这部分颗粒的作用是限制坯体产生过渡的收缩、裂纹、变形；粗骨料应占0-30%，不做粗骨料饰纹时可不用。

The so-called particle size distribution refers to the proportion of various particle sizes in the sludge. Generally, there are three kinds of particle sizes: fine powder (also known as plastic particles, less than 0.053), filling particles (0.053-1.2), coarse aggregate (ornamental particles, 1.2-2.4). The content of fine powder determines the plasticity of the mud, which should generally account for 35-50%. Filling particles should account for 20-65%. The role of these particles is to limit the shrinkage, cracking and deformation of the green body. Coarse aggregates should account for 0-30%. They are not used without coarse aggregate decoration.

我们生产内墙砖时一般只要求前两种颗粒（细粉料、填充性颗粒）的比例，若这一比例失调，生产出的砖可能会产生裂纹。

When we produce interior wall bricks, we usually only require the proportion of the first two kinds of particles (fine powder, filling particles). If this proportion is out of balance, the bricks produced may produce cracks.

使用河、湖淤泥时经常会遇到这样的问题。

Such problems are often encountered in the use of river and lake silt.

防治措施：使用两种以上的原料，调整粒径组成，确保颗粒级配合适。

Prevention and control measures: use more than two kinds of raw materials, adjust the particle size composition, to ensure the appropriate particle size.

二、管理原因造成的产品裂纹

2. Product Cracks Caused by Management Causes

1、生产工艺不合理（主要是掺混不匀）

1. The production process is unreasonable (mainly mixing unevenly)

两种或两种以上的原料用来造砖时，如果掺混不均匀会造成产品的裂纹。因为两种原料的干燥和焙烧收缩不可能一样，很容易形成内应力，干燥和焙烧后产生裂纹就不可避免。

When two or more kinds of raw materials are used to make bricks, uneven mixing will cause cracks in the products. Because the drying and calcination shrinkage of the two raw materials can not be the same, it is easy to form internal stress. Cracks are inevitable after drying and calcination.

防治措施：

Prevention and control measures:

改进工艺，设法掺混均匀。最好在进破碎机之前按比例掺混好，这样在通过破碎机、筛分、搅拌三道工序掺混后，原料的掺混效果会更佳。两种以上的原料单独破碎、筛分，再到搅拌机后掺混，很难达到理想的效果。而且原料的比重差别越大，其掺混效果越差，产品产生裂纹的可能性就越大。

Improve the process and try to mix evenly. It is better to mix the raw materials proportionally before entering the crusher, so that after mixing through three processes of crusher, screening and stirring, the mixing effect of raw materials will be better. More than two kinds of raw materials are crushed and screened separately, then mixed after mixer, it is difficult to achieve the desired effect. Moreover, the bigger the proportion difference of raw materials is, the worse the mixing effect is, and the greater the possibility of cracking is.

2、陈化条件不充分

2. Inadequate aging conditions

陈化条件不充分即陈化效果不好，也会造成产品的裂纹。

The inadequate aging conditions will result in poor aging effect and cracks in the products.

陈化，也叫闷料困存，目的是使水分充分渗透、泥料疏解、松散匀化。陈化必须具备四个条件：粒度、水分、时间、温度，这四个条件缺一不可。粒度越小，陈化效果会越好；进陈化库时的水分以达到成型水分为最佳；时间必须保证72小时以上；陈化库环境温度也应该尽量保持在10℃以上（温度越低需要的陈化时间越长）。

Aging, also known as stuffy material trapping, aims to make water fully permeable, mud dredging, loosening and homogenization. Aging must have four conditions: granularity, moisture, time and temperature, which are indispensable. The smaller the particle size is, the better the aging effect will be; the best water content is formed when entering the aging depot; the time must be more than 72 hours; the environmental temperature of the aging depot should also be kept above 10 C as far as possible (the lower the temperature, the longer the aging time is needed).

我们在生产中都有这样的经验：停产检修前存下的泥料，下次再生产时特别好用，这是因为陈化时间延长的原因；同样的泥料，夏天比冬天好用，这是因为夏季气温比冬季高的原因。

We all have such experience in production: the mud deposited before shutdown and maintenance is particularly useful in the next reproduction because of the prolonged aging time; the same mud is better in summer than in winter, because the temperature in summer is higher than in winter.

成型原因造成的产品裂纹

Product Cracks Caused by Forming Reasons

一、设备原因

I. Equipment Reasons

1、设备本身缺陷

1. Defects of equipment itself

由于设备本身某些参数设计不合理会造成产品裂纹，如搅拌机设计或制作不合理造成搅拌不匀、搅拌强度不够、搅拌时间短等。曹世濮老师在其讲义中曾举过这样的例子：同样的泥料搅拌2分钟，挤出砖坯的干燥裂纹为4%，而搅拌到3分钟以上，在同样的干燥条件下，干燥裂纹只有1%。

Due to the unreasonable design of some parameters of the equipment itself, product cracks will occur, such as the mixer design or production unreasonable, resulting in uneven mixing, inadequate mixing intensity, short mixing time and so on. Teacher Cao Shipu gave an example in his lecture: the drying cracks of extruded bricks were 4% when the same mud was stirred for 2 minutes, and only 1% when stirred for more than 3 minutes under the same drying conditions.

挤出机绞龙、机头(俗称机脖子)、机口等如设计不合理或加工不合格也会造成产品的裂纹。

Cracks may also occur in extruder winches, head (commonly known as neck) and mouth, such as unreasonable design or unqualified processing.

防治措施：合理选择设备

Preventive measures: reasonable selection of equipment

2、模具不合格

2. Unqualified Mould

生产空心砖时由于模具不合格会造成砖坯裂纹，轻者形成隐形裂纹，到干燥或焙烧后才会显现，严重时直接影响成型。

In the production of hollow bricks, due to the unqualified die will cause cracks in the brick billet, invisible cracks will be formed in the light, which will appear after drying or roasting, and will directly affect the forming in serious cases.

防治措施：选购合格的模具。空心砖的模具最好不要自己加工。个别砖厂为图省钱，自己加工空心砖摸具，看似省钱，其实得不偿失。因为自己加工的模具运行阻力大、调试时间长、砖坯废品率高、产量低，综合算起来

Preventive measures: Select qualified molds. Hollow brick moulds should not be processed by themselves. In order to save money, individual brick factories process hollow brick tools themselves, which seems to save money, but in fact it is not worth the loss. Because of the high resistance of the mould, the long debugging time, the high rejection rate of brick and billet, and the low output, the comprehensive calculation is made.