Laser-Heated Ca/Mg Oxide Production for Low-Impurity Calcination

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for producing oxides from carbonates and hydroxides of Ca and Mg, such as limestone, dolomite, and magnesite, result in impure products with high carbon dioxide emissions and are inefficient for fine-grained materials, limiting their use in industrial applications and resource exploitation.

Innovation Solution

A method involving endothermic reaction of solids with luminescent oxides of Ca and/or Mg using laser light to produce high-purity oxides, reducing impurities and carbon dioxide emissions, and forming aggregates with larger particle sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a Maerz furnace is used to bake limestone, then the limestone can be converted to oxide, but the oxide contains impurities such as sulfur content and ash content derived from fuel

Engineering Contradiction:
Improveoxide purityVSAvoidfuel-derived impurities
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the conventional Maerz furnace (mechanical/thermal system using fuel combustion) with a laser irradiation system. The laser directly heats the limestone particles through optical energy, eliminating the need for fuel combustion and thereby preventing the introduction of fuel-derived impurities such as sulfur content and ash content into the oxide product.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the heating method from indirect fuel-based heating to direct laser irradiation. By controlling laser power, irradiation time, and particle size distribution, the process achieves high-purity oxide production without the contaminants associated with traditional fuel combustion methods.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If a Maerz furnace is used to bake fine-grained limestone (10 mm or less), then the limestone can be converted to oxide, but the process is inefficient and time-consuming

Engineering Contradiction:
Improvebaking efficiencyVSAvoidbaking time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent replaces the large-sized Maerz furnace with a laser irradiation system that can directly and rapidly heat fine-grained limestone particles. The laser energy is efficiently absorbed by the small particles, enabling quick conversion to oxide without the time delays and inefficiencies associated with heating fine particles in a conventional furnace.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The laser irradiation process can be applied in controlled pulses or continuous modes, allowing for efficient processing of fine-grained limestone. The periodic or continuous laser energy input rapidly raises the temperature of small particles, achieving complete conversion in a short time period compared to conventional furnaces.

Inventive Principle:
Principle #19Periodic action

3Productivity

If a Maerz furnace uses fossil fuel to bake limestone, then the limestone can be converted to oxide, but a large amount of carbon dioxide is emitted

Engineering Contradiction:
Improveoxide productionVSAvoidcarbon dioxide emission
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the fossil fuel-based Maerz furnace with a laser irradiation system. The laser converts electrical energy (potentially from renewable sources) directly into optical energy for heating, eliminating the combustion of fossil fuels and the associated carbon dioxide emissions while maintaining oxide production capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent transforms the heating process from a harmful fossil fuel combustion method into a clean laser-based method. By using laser energy, the process eliminates carbon dioxide emission while still achieving the necessary thermal conversion of limestone to oxide, effectively converting a harmful process into a beneficial environmentally-friendly process.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 method achieves high-purity oxides with low carbon dioxide residual amounts, enabling high-quality industrial raw materials and energy storage solutions, while effectively utilizing fine-grained limestone and reducing carbon footprint.

Implementation Method 1

irradiating the oxide in the luminescent state with laser light; endothermically reacting the solid with heat from the oxide in the luminescent state that has absorbed the laser light

Methodology Applied
Scientific EffectLight absorption and heat conversion: Absorption (EM radiation)

Implementation Method 2

an oxide of Ca and/or Mg in a luminescent state involving continuous luminescence by heat radiation

Methodology Applied
Scientific EffectLuminescence by heat radiation: Thermal Radiation

Data Source

PatentEP4671208A1Method for endothermically reacting solid and method for producing oxide
Publication Date: 2025.12.31 ADACHI SEKKAI INDS
  • EP4671208A1 patent drawingFigure 1
  • EP4671208A1 patent drawingFigure 2(a)~2(b)
  • EP4671208A1 patent drawingFigure 3

AI summary

An improvement in purity of an oxide obtained by baking limestone or the like has been required, and with regard to a production method therefor, a reduction in carbon dioxide emission has been attracting attention as an important issue toward the achievement of a decarbonized society. Provided is a method of endothermically reacting a solid adjacent to an oxide of Ca and/or Mg in a luminescent state involving continuous luminescence by heat radiation, the method including: irradiating the oxide in the luminescent state with laser light; and endothermically reacting the solid with heat from the oxide in the luminescent state that has absorbed the laser light. Also provided is a method of producing a corresponding oxide from a carbonate of Ca and/or Mg serving as the solid.