CN111362678A - 一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法 - Google Patents
一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法 Download PDFInfo
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Abstract
本发明属于旱区农业节水灌溉技术领域,尤其涉及一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法。本发明制备的陶瓷粉具有在600‑650℃即可软化熔融的特点,因此由石英粉和陶瓷粉混合模压制成的坯体,只需在比600‑650℃略高的温度下即可烧制出满足力学性能、开口孔隙率和孔径要求的微孔陶瓷灌水器。在陶瓷制品的烧制过程中,烧结温度越高,陶瓷制品的收缩率越大。由于本发明微孔陶瓷灌水器的烧结温度仅为680‑720℃,远低于背景技术中对比文献报道的烧结温度,因此本发明制备的微孔陶瓷灌水器势必具有极低的收缩率,可大幅降低微孔陶瓷灌水器的制造和使用成本,极具农业推广潜力和市场前景。
Description
技术领域
本发明属于旱区农业节水灌溉技术领域,尤其涉及一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法。
背景技术
渗灌具有节水效率高和生产成本低的显著优点。微孔陶瓷内部存在大量相互连通的微孔道,这些微孔道具有很好的毛细作用,能对在其内部流动的水产生很好的消能作用,将其制成灌水器用于渗灌也可取得理想的灌溉效果。上世纪末,在印度、巴基斯坦、伊朗、中东和拉丁美洲等一些干旱、半干旱地区出现了利用陶罐进行渗灌的做法,这种灌溉方法虽然简陋,但具有很好的节水、节能和增产效果。
进入21世纪,为了实现微孔陶瓷渗灌的智能化和连续化,一些学者对微孔陶瓷灌水器的规范化制备进行了研究。文献1“粘土基微孔陶瓷渗灌灌水器制备与性能优化,农业机械学报,2015,46(4):183-188.”公开了一种微孔陶瓷灌水器,该灌水器是将粘土、炉渣和硅溶胶的混合料模压成坯体在1050-1100℃烧成,其中烧结温度为1075℃,炉渣掺量为10%-30%的灌水器综合性能最佳,抗弯强度为9.0-11.0MPa,线收缩率为3.8%-4.7%,开口孔隙率为36.8%-44.8%。文献2“硅藻土微孔陶瓷灌水器制备工艺优化,农业工程学报,2015,31(22):70-76.”公开了一种微孔陶瓷灌水器,该灌水器将粘土、硅藻土和硫酸钙的混合料模压成坯体在1060-1090℃烧成,其中烧结温度为1075℃,硅藻土掺量为15%的灌水器综合性能最佳,维氏硬度为448MPa、线收缩率为4.9%,开口孔隙率为26.3%,在10KPa水头的流量为1.64L/h。文献3“微孔陶瓷灌水器流量影响因素研究,农业机械学报,2016,47(4):73-78.”公开了一种微孔陶瓷灌水器,该灌水器是将粘土、炉渣和硅溶胶的混合料模压成坯体在1050-1100℃烧成,其中通过改变烧结温度改变收缩率,控制孔隙率,继而达到改变微孔陶瓷灌水器流量的目的。文献4“一种微孔陶瓷灌水器及其制备方法”(申请号201610511677.0)公开了一种微孔陶瓷灌水器,该灌水器是将石英砂、滑石粉、糊精和硅溶胶的混合料模压成坯体在1200-1300℃烧成。
上述文献报道的微孔陶瓷灌水器虽然均能够满足渗灌的性能要求,但很难满足农业生产的低成本要求,主要体现在灌水器的烧结温度高、烧结收缩率大、烧结变形严重这三个方面。烧结温度高意味着制造成本高,烧结收缩率大和变形严重会增加灌水器与灌溉管道的安装难度,为了确保与灌溉管道顺利安装,灌水器在安装前必须进行打磨整形,不但灌水器的使用成本高,而且耗时耗工。
发明内容
本发明针对上述现有技术存在的不足,提供一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法。
本发明解决上述技术问题的技术方案如下:一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法,步骤如下:
(1)将粒径为0.2-0.5mm的石英砂倒入氧化锆球磨罐中,向每100g石英砂中加入20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨30-50mi n,得到平均粒径为5-30μm的石英粉;
(2)取石灰石/方解石、滑石/白云石、钾长石、钠长石、钙长石、锌白和硼砂混合,得到B2O3:S iO2:Al2O3:ZnO:CaO:MgO:K2O:Na2O重量比为(34-42):(12-18):(6-9):(15-18):(5-9):(2-3):(3-5):(18-24)的混合料,将混合料倒入氧化锆球磨罐中,向每100g混合料中加入20-25颗直径为10-15mm的氧化锆磨球,利用行星式球磨机球磨180-240mi n,得到平均粒径为1-3μm的陶瓷粉;
(3)将步骤(1)的石英粉和步骤(2)的陶瓷粉按重量比(78-85):(15-22)混合,向每100g混合料中加入10-15g水和20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨20-40mi n,得潮湿的混合料;
(4)利用模具,采用单向模压法将步骤(3)潮湿的混合料模压成灌水器坯体,模压压力为6-8MPa,将坯体放入通风橱中自然阴干6-8h;
(5)将步骤(4)的灌水器坯体置于硅酸铝纤维毡上,放入高温炉中,先以20-25℃/mi n的速率升温至580-600℃,再以8-10℃/mi n的速率升温至680-720℃,保温30-60mi n后,以20-25℃/mi n的速率降温至500-520℃,再以3-5℃/mi n的速率降温至15-25℃,得到微孔陶瓷灌水器。
进一步,步骤(1)中,球磨机公转速度为150-210转/mi n,自转速度为120-180转/mi n。
进一步,步骤(2)中,球磨机公转速度为210-240转/mi n,自转速度为180-210转/mi n。
进一步,步骤(3)中,球磨机的公转速度为100-150转/mi n,自转速度为80-120转/mi n。
本发明的特点和有益效果在于:
本发明制备的陶瓷粉具有在600-650℃即可软化熔融的特点,因此由石英粉和陶瓷粉混合模压制成的坯体,只需在比600-650℃略高的温度下即可烧制出满足力学性能、开口孔隙率和孔径要求的微孔陶瓷灌水器。在陶瓷制品的烧制过程中,烧结温度越高,陶瓷制品的收缩率越大。由于本发明微孔陶瓷灌水器的烧结温度仅为680-720℃,远低于背景技术中对比文献报道的烧结温度,因此本发明制备的微孔陶瓷灌水器势必具有极低的收缩率,可大幅降低微孔陶瓷灌水器的制造和使用成本,极具农业推广潜力和市场前景。
附图说明
图1为本发明的工艺流程图;
图2为本发明微孔陶瓷灌水器的尺寸、收缩率和变形情况测试示意图。
具体实施方式
以下结合实例对本发明的原理和特征进行描述,所举实例只用于解释本发明,并非用于限定本发明的范围。
本发明实施例使用的原料中,石灰石成分为CaCO3(CaO·CO2,纯度≥98%,CaO占比56wt%);方解石成分为CaCO3(CaO·CO2,纯度≥96%,CaO占比56wt%);滑石成分为Mg3[Si4O10](OH)2(3MgO·4SiO2·H2O,纯度≥99%,MgO占比31.7wt%,SiO2占比63.4wt%);白云石成分为CaMg(CO3)2(CaO·MgO·2CO2,纯度≥98%,CaO占比40wt%,MgO占比28.5wt%);钾长石成分为KAlSi3O8(K2O·Al2O3·6SiO2,纯度≥95%,K2O占比16.9wt%,Al2O3占比18.4wt%,SiO2占比64.7wt%);钠长石成分为NaAlSi3O8(Na2O·Al2O3·6SiO2,纯度≥95%,Na2O占比11.8wt%,Al2O3占比19.4wt%,SiO2占比68.8wt%);钙长石成分为CaAl2Si2O8(CaO·Al2O3·2SiO2,纯度≥95%,CaO占比20.1wt%,Al2O3占比36.7wt%,SiO2占比43.2wt%);锌白成分为ZnO(纯度≥99%);硼砂成分为Na2B4O7·10H2O(Na2O·B2O3,纯度≥98%,Na2O占比16.3wt%,B2O3占比36.5wt%)。步骤(2)中B2O3、SiO2、Al2O3、ZnO、CaO、MgO、K2O和Na2O的重量比为各原料中相同氧化物的重量加和之比。
实施例1
一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法,步骤如下:
(1)将粒径为0.2-0.5mm石英砂倒入氧化锆球磨罐中,向每100g石英砂中加入20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨50mi n,球磨机公转速度为210转/mi n,自转速度为180转/mi n,得到平均粒径为5μm的石英粉;
(2)取石灰石、滑石、钾长石、钠长石、钙长石、锌白和硼砂混合,得到B2O3:S iO2:Al2O3:ZnO:CaO:MgO:K2O:Na2O重量比为42:12:6:15:5:2:3:24的混合料,将混合料倒入氧化锆球磨罐中,向每100g混合料中加入20-25颗直径为10-15mm的氧化锆磨球,利用行星式球磨机球磨240mi n,球磨机公转速度为240转/mi n,自转速度为210转/mi n,得到平均粒径为1μm的陶瓷粉;
(3)将步骤(1)的石英粉和步骤(2)的陶瓷粉按重量比85:15混合,向每100g混合料中加入15g水和20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨40mi n,球磨机的公转速度为100转/mi n,自转速度为80转/min,得潮湿的混合料;
(4)利用模具,采用单向模压法将步骤(3)潮湿的混合料模压成灌水器坯体,模压压力为8MPa,将坯体放入通风橱中自然阴干8h;
(5)将步骤(4)的灌水器坯体置于硅酸铝纤维毡上,放入高温炉中,先以25℃/mi n的速率升温至600℃,再以10℃/mi n的速率升温至720℃,保温30mi n后,以25℃/mi n的速率降温至520℃,再以5℃/mi n的速率降温至室温,得到微孔陶瓷灌水器。
实施例2
一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法,步骤如下:
(1)将粒径为0.2-0.5mm石英砂倒入氧化锆球磨罐中,向每100g石英砂中加入20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨50min,球磨机公转速度为150转/min,自转速度为120转/min,得到平均粒径为20μm的石英粉;
(2)取方解石、滑石、钾长石、钠长石、钙长石、锌白和硼砂混合,得到B2O3:SiO2:Al2O3:ZnO:CaO:MgO:K2O:Na2O重量比为34:18:9:18:9:3:5:18的混合料,将混合料倒入氧化锆球磨罐中,向每100g混合料中加入20-25颗直径为10-15mm的氧化锆磨球,利用行星式球磨机球磨240min,球磨机公转速度为210转/min,自转速度为180转/min,得到平均粒径为2μm的陶瓷粉;
(3)将步骤(1)的石英粉和步骤(2)的陶瓷粉按重量比78:22混合,向每100g混合料中加入15g水和20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨40min,球磨机的公转速度为100转/min,自转速度为80转/min,得潮湿的混合料;
(4)利用模具,采用单向模压法将步骤(3)潮湿的混合料模压成灌水器坯体,模压压力为8MPa,将坯体放入通风橱中自然阴干8h;
(5)将步骤(4)的灌水器坯体置于硅酸铝纤维毡上,放入高温炉中,先以20℃/mi n的速率升温至580℃,再以8℃/min的速率升温至720℃,保温30min后,以20℃/min的速率降温至500℃,再以3℃/min的速率降温至室温,得到微孔陶瓷灌水器。
实施例3
一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法,步骤如下:
(1)将粒径为0.2-0.5mm石英砂倒入氧化锆球磨罐中,向每100g石英砂中加入20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨30min,球磨机公转速度为150转/min,自转速度为120转/min,得到平均粒径为30μm的石英粉;
(2)取方解石、白云石、钾长石、钠长石、钙长石、锌白和硼砂混合,得到B2O3:SiO2:Al2O3:ZnO:CaO:MgO:K2O:Na2O重量比为38:15:8:16:7:2:4:21的混合料,将混合料倒入氧化锆球磨罐中,向每100g混合料中加入20-25颗直径为10-15mm的氧化锆磨球,利用行星式球磨机球磨180min,球磨机公转速度为210转/min,自转速度为180转/min,得到平均粒径为3μm的陶瓷粉;
(3)将步骤(1)的石英粉和步骤(2)的陶瓷粉按重量比82:18混合,向每100g混合料中加入10g水和20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨20min,球磨机的公转速度为150转/min,自转速度为120转/min,得潮湿的混合料;
(4)利用模具,采用单向模压法将步骤(3)潮湿的混合料模压成灌水器坯体,模压压力为6MPa,将坯体放入通风橱中自然阴干6h;
(5)将步骤(4)的灌水器坯体置于硅酸铝纤维毡上,放入高温炉中,先以25℃/min的速率升温至600℃,再以10℃/min的速率升温至680℃,保温60min后,以25℃/min的速率降温至520℃,再以4℃/min的速率降温至室温,得到微孔陶瓷灌水器。
实施例4
一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法,步骤如下:
(1)将粒径为0.2-0.5mm石英砂倒入氧化锆球磨罐中,向每100g石英砂中加入20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨40min,球磨机公转速度为180转/min,自转速度为150转/min,得到平均粒径为15μm的石英粉;
(2)取石灰石、白云石、钾长石、钠长石、钙长石、锌白和硼砂混合,得到B2O3:SiO2:Al2O3:ZnO:CaO:MgO:K2O:Na2O重量比为38:15:7:15:6:3:4:21的混合料,将混合料倒入氧化锆球磨罐中,向每100g混合料中加入20-25颗直径为10-15mm的氧化锆磨球,利用行星式球磨机球磨180min,球磨机公转速度为240转/min,自转速度为210转/min,得到平均粒径为2μm的陶瓷粉;
(3)将步骤(1)的石英粉和步骤(2)的陶瓷粉按重量比82:18混合,向每100g混合料中加入10g水和20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨20min,球磨机的公转速度为150转/min,自转速度为120转/min,得潮湿的混合料;
(4)利用模具,采用单向模压法将步骤(3)潮湿的混合料模压成灌水器坯体,模压压力为6MPa,将坯体放入通风橱中自然阴干6h;
(5)将步骤(4)的灌水器坯体置于硅酸铝纤维毡上,放入高温炉中,先以20℃/min的速率升温至580℃,再以8℃/min的速率升温至700℃,保温45min后,以20℃/min的速率降温至500℃,再以4℃/min的速率降温至室温,得到微孔陶瓷灌水器。
表1为实施例1-4所得微孔陶瓷灌水器、密度、开口孔隙率、孔径、收缩率和变形情况。
表1
微孔陶瓷灌水器的形状可根据灌溉的实际需要进行调节,本发明以最常用的圆筒形灌水器为例。如图2所示,圆筒形灌水器的主要尺寸包括直径和高度。在模压过程中,坯体的高度受加料量和模压压力的影响,无法准确控制,但坯体的直径只取决于模具,可以准确控制,因此灌水器的收缩率根据其直径的变化来评价。采用游标卡尺进行测量,为了减少误差,内径和外径各测量3个点计算平均收缩率,然后将内径和外径的收缩率再次平均作为灌水器的收缩率。另外,如图2所示,灌水器的变形情况根据灌水器的圆柱度进行评价,当灌水器的圆柱度不大于0.08,即认为灌水器未发生变形。
通过调节球磨速度和球磨时间,可以改变石英粉和陶瓷粉的粒径,通过将具有不同粒径的石英粉和陶瓷粉配合,可使烧制的微孔陶瓷灌水器具有不同的开口孔隙率和孔径,从而使微孔陶瓷灌水器具有不同的渗水性能,以满足不同作物的灌溉需求。如表1所示,实施例1-4制备的微孔陶瓷灌水器的抗压强度均大于25MPa,开口孔隙率均大于35%,相比于背景技术中对比文献报道的微孔陶瓷灌水器,本发明制备的微孔陶瓷灌水器具有更高的抗压强度和开口孔隙率,而且孔径可方便有效地调节。
本发明制备的微孔陶瓷灌水器具有收缩变形极低的特点。如表1所示,实施例1和实施例2中,当烧结温度为720℃时,所制备的微孔陶瓷灌水器的收缩率仅为0.03-0.04%,远低于背景技术中对比文献报道的收缩率。更重要的是,实施例3和实施例4中,当烧结温度为680-700℃时,所制备的微孔陶瓷灌水器没有任何收缩。另外,实施例1-4制备的微孔陶瓷灌水器的圆柱度均小于0.08,可以认为没有变形。
综上所述,在制备工艺方面,本发明微孔陶瓷灌水器的烧制温度比现有技术报道的烧制温度普遍低300-400℃,可大幅降低微孔陶瓷灌水器的制造成本;在灌水器性能方面,与现有技术相比,本发明制备的微孔陶瓷灌水器不但性能更优,而且没有收缩变形,在与灌溉管道安装前无需进行打磨整形,可进一步降低微孔陶瓷灌水器的制造成本。另外,与现有技术相比,本发明制备的微孔陶瓷灌水器由于无需打磨整形,在实际使用时还具有省时省工的显著优点,可显著降低微孔陶瓷灌水器的使用成本。
以上所述仅为本发明的较佳实施例,并不用以限制本发明,凡在本发明的精神和原则之内,所作的任何修改、等同替换、改进等,均应包含在本发明的保护范围之内。
Claims (4)
1.一种低温烧结无收缩变形的微孔陶瓷灌水器的制备方法,其特征在于,步骤如下:
(1)将粒径为0.2-0.5mm的石英砂倒入氧化锆球磨罐中,向每100g石英砂中加入20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨30-50min,得到平均粒径为5-30μm的石英粉;
(2)取石灰石/方解石、滑石/白云石、钾长石、钠长石、钙长石、锌白和硼砂混合,得到B2O3:SiO2:Al2O3:ZnO:CaO:MgO:K2O:Na2O重量比为(34-42):(12-18):(6-9):(15-18):(5-9):(2-3):(3-5):(18-24)的混合料,将混合料倒入氧化锆球磨罐中,向每100g混合料中加入20-25颗直径为10-15mm的氧化锆磨球,利用行星式球磨机球磨180-240min,得到平均粒径为1-3μm的陶瓷粉;
(3)将步骤(1)的石英粉和步骤(2)的陶瓷粉按重量比(78-85):(15-22)混合,向每100g混合料中加入10-15g水和20-25颗直径10-15mm的氧化锆磨球,利用行星式球磨机球磨20-40min,得潮湿的混合料;
(4)利用模具,采用单向模压法将步骤(3)潮湿的混合料模压成灌水器坯体,模压压力为6-8MPa,将坯体放入通风橱中自然阴干6-8h;
(5)将步骤(4)的灌水器坯体置于硅酸铝纤维毡上,放入高温炉中,先以20-25℃/min的速率升温至580-600℃,再以8-10℃/min的速率升温至680-720℃,保温30-60min后,以20-25℃/min的速率降温至500-520℃,再以3-5℃/min的速率降温至15-25℃,得到微孔陶瓷灌水器。
2.根据权利要求1所述的制备方法,其特征在于,步骤(1)中,球磨机公转速度为150-210转/min,自转速度为120-180转/min。
3.根据权利要求1所述的制备方法,其特征在于,步骤(2)中,球磨机公转速度为210-240转/min,自转速度为180-210转/min。
4.根据权利要求1所述的制备方法,其特征在于,步骤(3)中,球磨机的公转速度为100-150转/min,自转速度为80-120转/min。
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