Lime Mud Recycling via Pulverization and Hydration
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Solution Overview
Problem
The paper industry faces challenges in recycling by-products such as lime mud and lime kiln CaO, which are generated during the papermaking process, and finding effective methods to reuse them in a cost-effective and environmentally friendly manner.
Innovation Solution
A method involving pulverizing, burning, and hydrating these by-products to produce a hydrate, which can then be used to manufacture paper, improving their whiteness and quality, and enabling their reuse in the papermaking process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If by-products such as lime mud and lime kiln CaO are generated in the papermaking process, then the papermaking process can proceed, but the by-products need to be treated and cannot be reused
Solution Approach 1:
The patent applies parameter changes by subjecting the by-products to a series of transformations: pulverization (changing particle size), burning at 900-1,300°C for 0.5-3 hours (changing temperature and chemical composition), and hydration at 20-90°C for 3-12 hours (changing moisture content and chemical form). These parameter changes convert the by-products into a form suitable for papermaking reuse, resolving the contradiction between by-product treatment complexity and reuse potential.
2Loss of substance
If conventional by-product treatment methods are used, then the by-products can be managed, but they cannot be effectively reused in the papermaking process
Solution Approach 1:
The patent employs preliminary action by performing pulverization, burning, and hydration treatments on the by-products before they are reused in the papermaking process. This preliminary processing ensures that the by-products achieve the necessary quality standards (whiteness and fineness) in advance, making them reliable for papermaking application and enabling effective reuse.
3Manufacturing precision
If the by-products are directly used without treatment, then the process is simple, but the quality and whiteness of the recycled paper is poor
Solution Approach 1:
The patent converts the harmful or useless by-products into beneficial materials through a series of processing steps. The burning process at 900-1,300°C transforms the by-products into a form with improved whiteness and chemical properties, while the subsequent hydration further enhances the quality. This conversion process turns what was previously waste into a valuable resource for papermaking, achieving high paper quality despite the increased processing complexity.
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
This method allows for the environmentally friendly and cost-effective reuse of lime mud and lime kiln CaO, enhancing their whiteness to that of high-grade raw materials, thereby improving the quality of the recycled paper.
Implementation Method 1
burning the pulverized product to prepare a burned product
Implementation Method 2
burning the pulverized product to prepare a burned product
Implementation Method 3
hydrating the burned product to prepare a hydrate
Data Source
AI summary
A method of recycling a by-product generated in a papermaking process including, pulverizing a by-product produced in a papermaking process to prepare a pulverized product, burning the pulverized product to prepare a burned product, hydrating the burned product to prepare a hydrate; and manufacturing paper from the hydrate and a paper slurry is provided, which allows reuse of by-products generated in conventional papermaking processes such as lime mud and lime kiln CaO, which is environmentally friendly as well as cost-effective, and also the level of whiteness of the by-products such as lime mud and lime kiln CaO generated in a papermaking process can be improved to that of a high-grade raw material, making it possible to also improve the whiteness of paper.