玻璃窑用镁砖(MgO>95%)

1范围

  本文件规定了玻璃窑用镁砖(MgO≥95%)的分类、形状和尺寸、技术要求、试验方法、检验规则以及包装、标志、运输、储存和质量证明书。

  本文件适用于MgO>95%的玻璃窑用镁砖。

2规范性引用文件

  下列文件中的内容通过文中的规范性引用而构成本文件必不可少的条款。其中，注日期的引用文件，仅该日期对应的版本适用于本文件:不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。

  GB/T 2992.1耐火砖形状尺寸 第 1部分:通用砖

  GB/T 2997致密定形耐火制品体积密度、显气孔率和真气孔率试验方法

  GB/T 5069镁铝系耐火材料化学分析方法

  GB/T 5072耐火材料常温耐压强度试验方法

  GB/T 5073压蠕变试验方法耐火材料

  GB/T 7320耐火材料 热膨胀试验方法

  GB/T 7321定形耐火制品试样制备方法

  GB/T 10325定形耐火制品验收抽样检验规则

  GB/T 10326定形耐火制品尺寸、外观及断面的检查方法

  GB/T 16546定形耐火材料包装、标志、运输、储存和质量证明书的一般规定

  GB/T 18930耐火材料术语

  GB/T 21114耐火材料 X 射线荧光光谱化学分析 熔铸玻璃片法

  GB/T 30873耐火材料 抗热震性试验方法

  YB/T 370耐火材料 荷重软化温度试验方法(非示差-升温法)

3术语和定义

  GB/T 18930界定的术语和定义适用于本文件。

4分类、形状和尺寸

4.1分类

  产品按MgO含量分为MZ-95、MZ-96、MZ-97、MZ-98四个牌号。注:牌号中MZ是镁砖的汉语拼音首字母，阿拉伯数字为气化镁的百分含量。

4.2形状和尺寸

4.2.1产品按其形状分为直形砖和筒形砖。

4.2.2直形砖形状尺寸应符合GB/T 2992.1的规定，也可按用户要求进行商定:简形砖形状尺寸由供需双方商定。

5技术要求

5.1产品的断面不应有宽度大于0.5mm的裂纹。

5.2产品的尺寸允许偏差与外观质量应符合表1的规定，缺角由a、b、c三条线的长度表示，如图1所示，缺棱由e、f、g三条线的长度表示，如图2所示。

表1尺寸允许偏差与外观质量单位为毫米
项目	范围	指标
尺寸允许偏差	≤100	±1.0
	>100，≤200	±1.5
	>200，≤300	±2.0
	>300	±3.0
扭曲		≤0.5%
缺角		a+b+c≤40，不允许超过3处
缺棱		e+f+g≤60，不允许超过3处
裂纹长度	宽度<0.10	允许
	0.10≤宽度≤0.25	≤60
	宽度>0.25	不允许
注:特殊形状产品的外观质量和尺寸偏差山供需双方商定;直形砖和筒形砖按高度差由供需双方商定分档包装。

图1产品的缺角示意图

图2产品的缺棱示意图

5.3产品的理化性能指标应符台表2的规定。

表2产品的理化性能指标
项目			指标
			MZ-95		MZ-96		MZ-97		MZ-98
			直形砖	筒形砖	直形砖	筒形砖	直形砖	简形砖	直形砖	筒形砖
化学成分	MgO/%	μ0≥	95	95	96	96	96.7	96.7	97.2	97.2
		σ≥	-0.5		-0.3		-0.1
	SiO2/%	μ0≤	1.8	1.8	1.5	1.5	1	1	0.6	0.6
		σ≤	+0.2
	CaO/%	μ0≤	2.0	2.0	1.8	1.8	1.5	1.5	1.3	1.3
		σ≤	+0.2
物理性能	体积密度/(g/cm3)	μ0≥	2.95	2.93	2.98	2.95	3.00	2.98	3.02	3.00
		σ≥	-0.01
	显气孔率/%	μ0≤	17.0	18.0	16.0	17.0	15.5	16.5	15.5	16.5
		σ≤	+0.5
	常温耐压强度/MPa	μ0≥	70	60	70	60	70	60	70	60
		σ≥	-10
	荷重软化温度(0.2MPa，T0.6)/℃	μ0≥	1680	1680	1700
		σ≥	-20
	抗热震性(950℃，空气急冷)/次	μ0≥	10
	蠕变率/(0.2MPa，1500℃x50h/%)	μ0≥	–	–	–	–	-1.0	提供实测数据	-0.9	提供实测数据
	线膨胀率/%	–	提供实测数据
注:特殊产品的理化性能指标可由供需双方商定。

6试验方法

6.1试样的制备按GB/T 7321的规定。

6.2尺寸允许偏差和外观质量按GB/T 10326的规定

6.3化学成分按GB/T 5069 或GB/T 21114的规定。

6.4体积密度和显气孔率按GB/T 2997的规定。

6.5常温耐压强度按GB/T 5072的规定。

6.6荷重软化温度按YB/T 370的规定。

6.7直形砖抗热震性按GB/T 30873的规定:简形砖抗热震性按附录A的规定。

6.8直形砖蠕变率按GB/T 5073的规定:简形砖端变率按附录B的规定。

6.9线膨胀率按 GB/T 7320 的规定。

7检验规则

7.1检验分类

7.1.1出厂检验

  出厂检验项目包括化学成分、显气孔率、常温耐压强度、荷重软化温度;也可由供需双方商定。

7.1.2型式检验

  型式检验包括第5章的全部内容，有下列情况之一时，应进行型式检验:

  a)生产工艺或原材料有较大改变时;

  b)正常生产时，每年至少进行两次；

  c)停产半年以上，恢复生产时；

  d)出厂检验结果与上次型式检验结果有较大差异时。

7.2组批与抽样

7.2.1组批

  相同条件生产的产品按牌号及砖型进行组批，每150t产品为一批，不足150t时按一批计。

7.2.2抽样

  玻璃窑用镁砖(MgO95%)的抽样按GB/T 10325的规定。

7.3 合格判定规则

  产品的检验结果符合表2的规定时，判定批产品合格。若检验结果中有任一项指标不符合要求时,可从该批产品中随机抽取双倍样品对不合格项进行复检，复检结果全部符合要求时，则判定该批产品为合格。否则判定该批产品不合格。

8包装、标志、运输、储存和质量证明书

8.1包装、标志、运输和储存按GB/T 16546的规定进行。

8.2产品出厂时应附有质量证明书，质量证明书应注明生产厂名、需方名称、产品名称、牌号登记及生产批号、质检专用章、签发人、检验结果、执行文件编号或供需双方约定等。

 

 

 

Magnesium brick for glass kiln (MgO>95%)

1 Range

  This document specifies the classification, shape and size, technical requirements, test methods, inspection rules, as well as packaging, marking, transportation, storage and quality certificates of magnesium bricks for glass kilns (MgO≥95%).

  This document applies to magnesium bricks for glass kilns with MgO>95%

2 Normative reference documents

  The contents of the following documents constitute the essential provisions of this document through normative references in the text. If a reference file is dated, only the version corresponding to that date applies to this file. If a reference file is undated, its latest version (including all modification orders) applies to this file.

  GB/T 2992.1 Shape and dimensions of refractory bricks – Part 1: general purpose bricks

  Test method for bulk density, apparent porosity and true porosity of GB/T 2997 compact shaped refractory products

  GB/T 5069 method for chemical analysis of MG-Al refractories

  GB/T 5072 refractories – normal temperature compressive strength test method

  GB/T 5073 pressure creep test methods Refractory materials

  GB/T 7320 refractory thermal expansion test method

  GB/T 7321 shaped refractory product sample preparation method

  GB/T 10325 shaped refractory products acceptance sampling inspection rules

  GB/T 10326 shaped refractory products size, appearance and section inspection method

  GB/T 16546 General requirements for packaging, marking, transport, storage and quality certificates for shaped refractory materials

  GB/T 18930 refractory terminology

  GB/T 21114 refractories by X-ray fluorescence spectrochemical analysis of fused cast glass sheets

  Test method for thermal shock resistance of GB/T 30873 refractories

  Test method for load softening temperature of YB/T 370 refractories (non-differential warming method)

3 Terms and definitions

  The terms and definitions defined in GB/T 18930 apply to this document.

4 Classification, shape and size

4.1 Classification

  Products according to MgO content is divided into MZ-95, MZ-96, MZ-97, MZ-98 four grades. Note: MZ in the brand is the initial letter of the Chinese pinyin of the magnesium brick, and the Arabic number is the percentage of the vaporized magnesium.

4.2 Shape and size

4.2.1Products are divided into straight bricks and cylindrical bricks according to their shape.

4.2.2 The shape and size of the straight brick shall comply with the provisions of GB/T 2992.1, and can also be agreed according to the requirements of users: the shape and size of the simple brick shall be agreed by the supply and demand parties.

5 Technical Requirements

5.1 The section of the product shall not have cracks with a width greater than 0.5mm.

5.2 The size permissible deviation and appearance quality of the product shall comply with the provisions of Table 1. The missing Angle is represented by the length of three lines a, b and c, as shown in Figure 1; the missing edge is represented by the length of three lines e, f and g, as shown in Figure 2.

Table 1 Dimensions permissible deviation and apparent mass in millimeters
Item	Radius	Index
Allowable deviation of dimension	≤100	±1.0
	>100，≤200	±1.5
	>200，≤300	±2.0
	>300	±3.0
Contort		≤0.5%
Missing corner		The value of a+b+c≤40 cannot exceed three
wane		e+f+g≤60, the value cannot exceed three
Crack length	Breadth<0.10	Permit
	0.10≤Breadth≤0.25	≤60
	Breadth>0.25	Not allow
Note: The appearance quality and size deviation of special shape products shall be agreed by the supply and demand parties; Straight brick and cylindrical brick according to the height difference by the supply and demand parties to agree on the packaging.

Figure 1 Schematic diagram of missing corners of the product

FIG. 2 Schematic diagram of the missing edge of the product

5.3 The physical and chemical properties of the product shall comply with the provisions of Table 2.

Table 2 Physical and chemical properties of the products
Item			Index
			MZ-95		MZ-96		MZ-97		MZ-98
			Straight brick	Cylindrical brick	Straight brick	Cylindrical brick	Straight brick	Cylindrical brick	Straight brick	Cylindrical brick
Chemical composition	MgO/%	μ0≥	95	95	96	96	96.7	96.7	97.2	97.2
		σ≥	-0.5		-0.3		-0.1
	SiO2/%	μ0≤	1.8	1.8	1.5	1.5	1	1	0.6	0.6
		σ≤	+0.2
	CaO/%	μ0≤	2.0	2.0	1.8	1.8	1.5	1.5	1.3	1.3
		σ≤	+0.2
Physical property	Bulk density/(g/cm3)	μ0≥	2.95	2.93	2.98	2.95	3.00	2.98	3.02	3.00
		σ≥	-0.01
	Apparent porosity/%	μ0≤	17.0	18.0	16.0	17.0	15.5	16.5	15.5	16.5
		σ≤	+0.5
	Compressive strength at room temperature /MPa	μ0≥	70	60	70	60	70	60	70	60
		σ≥	-10
	Load softening temperature (0.2MPa, T0.6)/℃	μ0≥	1680	1680	1700
		σ≥	-20
	Thermal shock resistance (950℃, air cooling)/ time	μ0≥	10
	Creep rate /(0.2MPa, 1500℃x50h/%)	μ0≥	–	–	–	–	-1.0	Provide measured data	-0.9	Provide measured data
	Linear expansion rate /%	–	Provide measured data
Note: The physical and chemical properties of special products can be agreed by the supply and demand parties.

6 Test methods

6.1 The preparation of the sample shall be in accordance with GB/T 7321.

6.2 Permissible size deviation and appearance quality in accordance with GB/T 10326

6.3 Chemical composition according to GB/T 5069 or GB/T 21114.

6.4 The bulk density and apparent porosity shall be specified in GB/T 2997.

6.5 The compressive strength at room temperature shall be specified in GB/T 5072.

6.6 Load softening temperature according to YB/T 370.

6.7 The thermal shock resistance of straight brick is in accordance with GB/T 30873: The thermal shock resistance of simple brick is in accordance with Appendix A.

6.8 The creep rate of straight brick shall be in accordance with GB/T 5073; the end variability of simple brick shall be in accordance with Appendix B.

6.9 The linear expansion rate is specified in GB/T 7320.

7 Inspection Rules

7.1 Inspection Classification

7.1.1 Factory inspection

  Factory inspection items include chemical composition, apparent porosity, normal temperature compressive strength, load softening temperature; It can also be agreed between the supply and demand parties.

7.1.2 Type inspection

  Type inspection shall include all the contents of Chapter 5, and shall be carried out under any of the following circumstances:

  a) When there is a major change in the production process or raw materials;

  b) During normal production, at least twice a year;

  c) stop production for more than half a year and resume production;

  d) When there is a big difference between the factory inspection result and the last type inspection result.

7.2 Batch and sampling

7.2.1 Batch Group

  The products produced under the same conditions are grouped according to the brand and brick type, each 150t product is a batch, and less than 150t is counted according to a batch.

7.2.2 Sampling

  The sampling of magnesia bricks for glass kiln (MGO 95%) is according to GB/T 10325.

7.3 Qualification Rules

  When the inspection results of the products comply with the provisions of Table 2, the products of the batch are judged to be qualified. If any index in the test results does not meet the requirements, double samples can be randomly drawn from the batch of products for reinspection of unqualified items, and when the reinspection results all meet the requirements, the batch of products will be judged as qualified. Otherwise, this batch of products is judged to be unqualified.

8 Packing, marking, transportation, storage and quality certificate

8.1 Packing, marking, transportation and storage shall be carried out in accordance with GB/T 16546.

8.2 The product shall be accompanied by a quality certificate when it leaves the factory. The quality certificate shall indicate the name of the manufacturer, the name of the demander, the name of the product, the brand registration and production lot number, the special seal for quality inspection, the issuer, the inspection result, the execution document number or the agreement between the supply and demand parties.