Foundry Sand Mixture Recovery via Thermal Binder Dissolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for processing foundry sand mixtures are not cost-effective, resource-saving, or productive enough for further use, particularly in separating molding sand from inorganic binder residues and additives.
Innovation Solution
A method involving mixing the foundry sand mixture with cleaning water at a temperature of 80-100 °C to dissolve inorganic binder residues, followed by separation, and optionally preheating using waste heat, with mechanical comminution to increase surface area and efficiency, and pH adjustment for broader application compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical comminution is performed to increase surface area, then separation efficiency is improved, but energy consumption increases
Solution Approach 1:
The patent applies parameter changes by optimizing the comminution process parameters (particle size reduction, surface area increase) to achieve sufficient separation efficiency while controlling energy consumption. The slurry temperature and composition parameters are also adjusted to enhance binder dissolution without excessive energy input.
Solution Approach 2:
The patent replaces purely mechanical separation with a chemical dissolution process. By using water to dissolve the inorganic binder at elevated temperatures, the method substitutes mechanical comminution with thermal-chemical treatment, reducing the need for intensive mechanical energy input while achieving effective separation.
2Manufacturing precision
If process temperature is increased to 80-100°C to dissolve inorganic binder, then separation completeness is improved, but energy consumption increases
Solution Approach 1:
The patent applies parameter changes by optimizing the slurry temperature to the specific range of 80-100°C. This temperature parameter change maximizes the dissolution rate and completeness of the inorganic binder while considering energy consumption constraints. The temperature is high enough to achieve near-complete separation but controlled to avoid excessive energy input.
Solution Approach 2:
The patent utilizes phase transitions by heating the slurry to 80-100°C to enhance the solubility and dissolution kinetics of the inorganic binder. The thermal energy induces phase changes in the binder material, transitioning it from a bound state to a dissolved state, thereby achieving complete separation without requiring excessive mechanical or chemical energy.
3Productivity
If process time is reduced for efficient processing, then productivity is improved, but separation completeness may deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the process time within the 5-60 minute range. This time parameter is sufficient to achieve complete binder dissolution and separation while maintaining high productivity. The elevated temperature accelerates the dissolution kinetics, allowing short process times without compromising separation completeness.
Solution Approach 2:
The patent replaces time-intensive mechanical separation processes with rapid thermal-chemical dissolution. The water-based dissolution at 80-100°C occurs much faster than mechanical separation methods, enabling short process times (5-60 minutes) while achieving complete separation, thus resolving the contradiction between productivity and separation completeness.
4Manufacturing precision
If water is used to dissolve and rinse inorganic binder residues, then separation effectiveness is improved, but water consumption increases
Solution Approach 1:
The patent utilizes phase transitions by heating the water to 80-100°C, which significantly enhances the solubility and dissolution capacity of water for inorganic binders. The thermal energy induces phase changes in the binder material, allowing more complete dissolution with less water volume, thereby reducing water consumption while maintaining high separation effectiveness.
Solution Approach 2:
The patent applies parameter changes by optimizing the water temperature and possibly the water-to-sand ratio. The elevated temperature parameter increases the dissolving power of water, enabling effective binder removal with reduced water consumption compared to cold water rinsing methods.
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 enables efficient separation of molding sand from inorganic binder residues in short process times, integrates into a water- and energy-saving cycle, and prepares the sand for reuse with minimal costs, allowing for further processing into molding materials with either inorganic or organic binders.
Implementation Method 1
Mixing the foundry sand mixture with cleaning water to form a slurry in order to dissolve the inorganic binder residues contained in the foundry sand mixture
Implementation Method 2
the process temperature of the slurry formed from the cleaning water and the foundry sand mixture in step a) is now 80 - 100 °C
Data Source
Figure 1
AI summary
The invention provides a method for the cost-effective, resource-saving, and highly productive recovery of molding sand (F) from a foundry sand mixture (G) comprising at least a proportion (FAB) of molding material fragments or loose molding material grains that arise during the demolding of a casting from a mold as a result of the destruction of cores or mold parts representing the casting, which are formed from the molding sand (F) as well as an inorganic binder and optionally one or more additives for adjusting the properties of the molding material, wherein the method comprises the steps a) mixing the foundry sand mixture (G) with cleaning water (RW) to form a slurry (S) in order to dissolve the inorganic binder residues (AB) and optionally present additives contained in the foundry sand mixture (G) from the molding sand (F) and to rinse them out of the foundry sand mixture (G),and b) separating the cleaning water (RWK) contaminated with the inorganic binder residues (AB) from the molding sand (F) contained in the slurry (S), wherein the process temperature of the slurry (S) formed from the cleaning water and the foundry sand mixture (G) (step a)) is 50 - 200 °C.