标准编号:	GB/T 36141-2018
中文名称:	建筑石膏相组成分析方法
英文名称:	Methods for phase composition analysis of calcined gypsum
中标分类:	Q27    粘结材料
行业分类:	GB    国家标准
ICS分类:	91.100.10 91.100.10    水泥、石膏、石灰、砂浆 91.100.10
发布机构:	国家市场监督管理总局、中国国家标准化管理委员会
发布日期:	2018-05-14
实施日期:	2019-4-1
标准状态:	现行
翻译语言:	英文
文件格式:	PDF
中文字符数:	11000 字
翻译价格(元):	770.00 元
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.



This standard is developed in accordance with the rules given in GB/T 1.1-2009.



This standard was proposed by China Building Materials Federation.



This standard is under the jurisdiction of SAC/TC 195 National Technical Committee on Lightweight and Decorative Building Materials of Standardization Administration of China.



Introduction



The issuing body of this document draws attention to the fact that claims of compliance with this document may involve the use of a patent in ZL 2011 10033606.1 Method for quickly analyzing phase composition of calcined gypsum.



The issuing body of this document takes no position concerning the evidence, validity and scope of this patent right.



The patent holder has assured the issuing body of this document that he allows the user of this document to apply the relevant technical content of this patent for free. The patent holders’ statements have been put on records at the issuing body of this document. The relevant information may be obtained through the following contact information:



Name of patent holder: Shanghai Research Institute (Group) of Building Sciences Co., Ltd.



Address: No. 75, Wanping South Road, Xuhui District, Shanghai



http://www.jk.sh.cn/



Attention is drawn to the possibility that some other contents of this document may also be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.







Methods for phase composition analysis of calcined gypsum



1 Scope



This standard specifies the oven method and moisture analyzer method for phase composition analysis of calcined gypsum.



This standard is applicable to the analysis of content of three phases, namely soluble anhydrite (AIII), hemihydrate gypsum (HH) and dihydrate gypsum (DH) in calcined gypsum powder prepared by calcination of dihydrate gypsum (natural gypsum or industrial by-product gypsum).



2 Normative references



The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.



GB/T 6682 Water for analytical laboratory use - Specification and test methods



3 Principle



3.1 Soluble anhydrite (AIII) in calcined gypsum



Soluble anhydrite (AIII) is hygroscopic and may convert to hemihydrate gypsum (HH) by absorbing water in the air, so soluble anhydrite (AIII) and attached water will not be present in the sample at the same time. Soluble anhydrite (AIII) can be hydrated to hemihydrate gypsum in 95% aqueous ethanol, but under the same conditions hemihydrate gypsum (HH) cannot be hydrated to dihydrate gypsum (DH), so the content of the soluble anhydrite (AIII) may be calculated by determining the increment of dydrated soluble anhydrite in 95% aqueous ethanol. The hydration reaction formula is as follows:



CaSO4+0.5H2O=CaSO4·0.5H2O



Calculate the content of soluble anhydrite (AIII) using the chemical reaction formula.



If no soluble anhydrite (AIII) is present in the sample, the mass fraction of the attached water may be calculated based on the mass by which the sample mass before drying is greater than that after constant weight drying.



 

3.2 Hemihydrate gypsum (HH) in calcined gypsum



Hemihydrate gypsum (HH) and soluble anhydrite (AIII) may all be hydrated to dihydrate gypsum (DH) in pure water, and the content of dihydrate gypsum (DH) may be calculated by determining the increment of calcined gypsum due to hydration in pure water, i.e., determining the total amount of dihydrate gypsum (DH) fromed by hemihydrate gypsum (HH) and soluble anhydrite (AIII), minus the content of soluble anhydrite (AIII) determined by the principle in 3.1 (where there is no anhydrite (AIII) phase, the mass loss due to drying of attached water shall be added). The hydration reaction formula is as follows:



CaSO4·0.5H2O+1.5H2O＝CaSO4·2H2O



CaSO4+2H2O=CaSO4·2H2O



3.3 Residual dihydrate gypsum (DH) in calcined gypsum



When calcined gypsum is heated to 200°C or above, dihydrate gypsum (DH) is dehydrated into soluble anhydrite (AIII), and the total amount of dehydration is the sum of those of dihydrate gypsum (DH), hemihydrate gypsum (HH) and attached water, which subtract the dehydration of hemihydrate gypsum (HH) and attached water is the content of residual dihydrate gypsum (DH). The thermal dehydration reaction formula is as follows:



CaSO4·2H2O CaSO4+2H2O



CaSO4·0.5H2O CaSO4+0.5H2O



4 Reagents and materials



In the analysis, Class-III water or above according to GB/T 6682 shall be used, and the ethanol solution shall be analytical reagent with a concentration of 95%.



5 Apparatus



5.1 Electronic balance, with a division of 0.0001 g.



5.2 electrically heated drying oven (baking oven), with the temperature capable of reaching 230℃ and temperature controlling accuracy of ±3℃, and equipped with automatic temperature controller.



5.3 Moisture analyzer, with a division of not less than 0.001g; usage temperature control range: 50℃~200℃; temperature control accuracy: ±1℃.



5.4 Vessel: weighing bottle with cover, with specification of Φ50 mm×30 mm.



5.5 Desiccator: contained with dried color changing silica gel.



6 Test conditions



The temperature and relative humidity of the laboratory shall be 23℃±2℃ and 50%±5%, respectively.



7 Sampling and preparation of specimens



The sample shall be taken quickly by quartering method, the amount of sample shall be about 150 g, which is put into the dried ground bottle, tightly closed, and put into the desiccator for 24 h and then immediately carried out the test.



For the test, control the weighing time within 2 min, put the remaining sample back into the desiccator immediately after covering.

Foreword i
Introduction ii
1 Scope
2 Normative references
3 Principle
4 Reagents and materials
5 Apparatus
6 Test conditions
7 Sampling and preparation of specimens
8 Oven method (Method A)
9 Moisture analyzer method (Method B)
10 Test report

ICS 91.100.10
Q 27
中华人民共和国国家标准
GB/T 36141—2018
建筑石膏相组成分析方法
Methods for phase composition analysis of calcined gypsum
2018-05-14发布 2019-04-01实施
国家市场监督管理总局
中国国家标准化管理委员会
发布
前言
本标准按照GB/T 1.1—2009给出的规则起草。
本标准由中国建筑材料联合会提出。
本标准由全国轻质与装饰装修建筑材料标准化技术委员会(SAC/TC 195)归口。
引 言
本文件的发布机构提请注意，声明符合本文件时，可能涉及到相关专利ZL 2011 10033606.1《一种建筑石膏的快速相组成分析方法》的使用。
本文件的发布机构对于该专利的真实性、有效性和范围无任何立场。
该专利持有人已向本文件的发布机构保证，他同意本文件的使用者可免费使用该专利的相关技术内容。该专利持有人的声明已在本文件的发布机构备案。相关信息可以通过以下联系方式获得：
专利持有人姓名：上海市建筑利.学研究院(集团)有限公司
地址：上海市徐汇区宛平南路75号
http：//www.jk.sh.cn/
注意除上述专利外，本文件的某些内容仍可能涉及专利。本文件的发布机构不承担识别这些专利的责任。
建筑石膏相组成分析方法
1范围
本标准规定了建筑石膏相组成分析方法的烘箱法和水分测定仪法。
本标准适用于由二水石膏(天然石膏或工业副产石膏)煅烧制备的建筑石膏粉中可溶性无水石膏(AⅢ)、半水石膏(HH)、二水石膏(DH)三相含量的分析。
2规范性引用文件
下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是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 6682分析实验室用水规格和试验方法
3原理
3.1 建筑石膏中的可溶性无水石膏(AⅢ)
可溶性无水石膏(AⅢ)具有吸湿性，其吸收空气中的水可以转化为半水石膏(HH)，因此可溶性无水石膏(AⅢ)与附着水不会同时存在于样品中。可溶性无水石膏(AⅢ)在95％的乙醇水溶液中能水化成半水石膏，在同等条件下半水石膏(HH)不能水化成二水石膏(DH)，因此可通过测定可浴性无水石膏(AⅢ)在95％乙醇水溶液中水化的增量来计算其含量。其水化反应式如下：
CaSO4+0.5H2O=CaSO4·0.5H2O
按化学反应式计算可溶性无水石膏(AⅢ)含量。
若样品中无可溶性无水石膏(AⅢ)存在时，样品烘干前质量大于烘干恒重后的质量，可算出附着水的质量分数。
3.2建筑石膏中的半水石膏(HH)
半水石膏(HH)和可溶性无水石膏(AⅢ)在纯水中可全部水化为二水石膏(DH)，测定建筑石膏在纯水中的水化增量，即测定半水石膏(HH)和可溶性无水石膏(AⅢ)形成二水石膏(DH)的总量，减去用3.1原理测得的可溶性无水石膏(AⅢ)的含量(当不含无水石膏(AⅢ)相时，应加上附着水被烘出的质量损失)，即可计算出半水石膏(HH)的含量。其水化反应式如下：
CaSO4·0.5H2O+1.5H2O＝CaSO4·2H2O
CaSO4+2H2O=CaSO4·2H2O
3.3 建筑石膏中残留的二水石膏(DH)
将建筑石膏加热到200℃或以上，二水石膏(DH)脱水变成可溶性无水石膏(AⅢ)，其脱水总量为二水石膏(DH)与半水石膏(HH)、附着水的脱水量的总和，减去半水石膏(HH)与附着水的脱水量，即可计算出残留的二水石膏(DH)的含量。其加热脱水反应式如下：
CaSO4·2H2O CaSO4+2H2O
CaSO4·0.5H2O CaSO4+0.5H2O
4试剂和材料
分析过程中用水应符合GB/T 6682中三级或三级以上水的要求；乙醇溶液应为浓度为95％的分析纯试剂。
5仪器设备
5.1电子天平，分度值为0.000 1 g。
5.2 电热干燥箱(烘箱)，温度能达到230℃，控温精度±3℃，带有温度自动控制器。
5.3水分测定仪，分度值不小于0.001 g；使用温度控制范围：50℃～200℃；控温精度：±1℃。
5.4容器：带盖称量瓶，规格：Φ50 mm×30 mm。
5.5干燥器：盛有干燥的变色硅胶。
6试验条件
实验室温度为23℃±2℃；
相对湿度为50％±5％。
7取样及试样制备
试验用样品采用四分法快速取样，取样量约150 g，装入已烘干的磨口瓶，紧密盖严，放入干燥器中，放置24 h后立即进行试验。
试验时每次称量时间控制在2 min以内，剩余样品盖好立即放回干燥器内。
8烘箱法(A法)
8.1 附着水与可溶性无水石膏(AⅢ)含量的测定
8.1.1 试验步骤
8.1.1.1 称量已烘干至恒重的空称量瓶m01。
8.1.1.2称取约5 g试样放入称量瓶中，精确至0.000 1 g，记录质量m1。
8.1.1.3顺着称量瓶边缘缓慢加入95％乙醇溶液约5 mL，轻轻振荡使试样湿润均匀，静置10 min。
8.1.1.4将上述称量瓶敞开盖放入(40±3)℃烘箱中(盖子同时放在烘箱中加热)，加热不少于6 h。
8.1.1.5取出称量瓶立即盖上盖子，放入干燥器中于室温下冷却15 min，称量。
8.1.1.6再将称量瓶敞开盖放入烘箱内于同样的温度下加热1 h，按8.1.1.5步骤冷却、称量；如此反复，当加热时间相隔1 h的两次称量之差不大于0.5 mg即为恒重，记录质量m2。
8.1.2结果计算
8.1.2.1 当m1>m2时，附着水含量以质量分数wa1计，按式(1)进行计算，此时可溶性无水石膏(AⅢ)含量wA1=0。
(1)
式中：
wa1——试样中附着水的质量分数；
m01——空称量瓶质量，单位为克(g)；
m1——加入乙醇溶液前(称量瓶+样品)的质量，单位为克(g)；
m2——加入乙醇溶液并烘干至恒重后(称量瓶+样品)的质量，单位为克(g)。
8.1.2.2当m1m2时：按式(4)进行计算：
wHH1=5.37×(c1+wa1)×100％ (4)
式中：
wHH1——试样中半水石膏(HH)的质量分数；
c1——试样水化后的质量变化分数；
wa1——试样中附着水的质量分数。
当m1m2时：按式(7)进行计算：
wDH1=4.78×[(d1-wa1)-0.062×wHH1]×100％ (7)
式中：
WDH1——试样中二水石膏(DH)的质量分数；
d1——试样在加热过程中质量的变化分数；
wa1——试样中附着水的质量分数；
wHH1——试样中半水石膏(HH)的质量分数。
当m1m8时，附着水含量以质量分数wa2计，按式(9)进行计算，此时可溶性无水石膏(AⅢ)含量wA2=0。
(9)
式中：
wa2——试样中附着水的质量分数；
m04——空样品盘质量，单位为克(g)；
m7——加入乙醇溶液前(样品盘+样品)的质量，单位为克(g)；
m8——加入乙醇溶液并烘干至恒重后(样品盘+样品)的质量，单位为克(g)。
9.2.2.2当m7m8时：按式(12)进行计算：
wHH2=5.37×(c2+wa2)×100％ (12)
式中：
wHH2——试样中半水石膏(HH)的质量分数；
c2——试样水化后的质量变化分数；
wa2——试样中附着水的质量分数。
当m7m8时：按式(15)进行计算：
wDH2=4.78×[(d2-wa2)-0.062×wHH2]×100％ (15)
式中：
wDH2——试样中二水石膏(DH)的质量分数；
d2——试样在加热过程中质量的变化分数；
wa2——试样中附着水的质量分数；
wHH2——试样中半水石膏(HH)的质量分数。
当m7