Oyster Shell Porcelain Paste Composition for High Whiteness
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Solution Overview
Problem
Current processes for producing porcelain using bone ash are inefficient and generate significant waste, with a need for alternative natural resources that can replicate the properties of bone china without degrading the final product.
Innovation Solution
A porcelain paste composition comprising kaolin, feldspar, calcium phosphate derived from oyster shells, and optionally silica, with a specific Ca/P molar ratio, which replaces bone powder and allows for the direct incorporation of oyster shell waste, enabling firing at a lower temperature in an oxidizing atmosphere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If bone ash is used in porcelain paste, then whiteness and impact resistance are improved, but environmental pollution and waste generation increase
Solution Approach 1:
The invention changes the chemical composition parameters by replacing bone ash (calcium phosphate from animal bones) with oyster shell powder (calcium carbonate from marine shells). This substitution maintains the calcium content necessary for whiteness and mechanical strength while eliminating the environmental pollution associated with bone ash production and disposal.
Solution Approach 2:
The invention uses oyster shell powder, an abundant natural waste material, as a substitute for bone ash. Oyster shells are readily available from shellfish processing industries, making this a cost-effective and environmentally friendly alternative that reduces dependence on animal-derived materials.
2Illumination intensity
If oyster shell powder is added to porcelain paste, then whiteness is improved, but firing temperature control becomes more challenging
Solution Approach 1:
The invention optimizes the proportion of oyster shell powder in the porcelain paste to balance whiteness enhancement with firing temperature control. By carefully adjusting the calcium carbonate content and corresponding adjustments to other components like kaolin and feldspar, the paste achieves high whiteness while maintaining stable firing characteristics at temperatures between 1200-1400°C.
3Loss of substance
If natural calcium resources are used to replace bone ash, then waste recycling is improved, but manufacturing precision may be compromised
Solution Approach 1:
The invention applies preliminary processing steps to oyster shells including cleaning, drying, grinding, and sieving before incorporation into the porcelain paste. These pre-treatment operations ensure that the oyster shell powder is free from contaminants and has a consistent particle size distribution, thereby maintaining manufacturing precision while enabling effective waste recycling.
Solution Approach 2:
The invention carefully controls the chemical and physical parameters of the oyster shell powder, including calcium carbonate purity, particle size distribution, and moisture content. By standardizing these parameters, the invention ensures consistent porcelain quality while maximizing the use of recycled oyster shell waste.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting porcelain exhibits high whiteness, mechanical resistance, and efficient waste recycling, with improved whiteness and mechanical properties compared to traditional bone china and Limoges porcelain, while reducing environmental impact through the use of abundant oyster shell waste.
Implementation Method 1
calcined and finely ground again
Implementation Method 2
produce calcium phosphate from oyster shells
Implementation Method 3
firing the paste at a temperature above 1180°C
Data Source
Figure 1
AI summary
A porcelain paste for firing, composed of water and a mineral fraction comprising 20 to 40% by mass of kaolin, 15 to 30% by mass of feldspar, 30 to 50% by mass of calcium phosphate, and optionally silica at a concentration of 10% by mass or less, the calcium in the calcium phosphate being derived from oyster shells. This paste can advantageously be fired at a temperature between 1180°C and 1260°C under an oxidizing atmosphere. It may also contain between 0.1% and 10% by mass of micronized raw oyster shell powder with a particle size of 150 µm or less. Porcelain prepared in this way, with or without the addition of raw micronized oyster shell powder, exhibits superior whiteness and strength compared to Limoges porcelain.