Gold Concentration Analysis via X-Ray Normalization
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Solution Overview
Problem
Current methods for determining the concentration of gold and other elements in mineral deposits, such as fire assay and gamma-activation analysis, face challenges including labor-intensive sample preparation, high temperature requirements, sampling errors, and sensitivity to variations in X-ray source energy and temperature, leading to inaccurate results.
Innovation Solution
A method involving the simultaneous irradiation of a sample and a reference material with Bremsstrahlung X-rays, followed by detection of deactivation gamma-rays, with normalization of the target element's signal by the reference material's signal to correct for variations in X-ray source power and energy, using a reference material with a stable cross-section ratio and half-life similar to the target element to minimize measurement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fire assay method is used to determine gold concentration, then the analysis can be performed with established industry standard, but the procedure requires complicated sample preparation, is very labour intensive, involves extremely high temperatures, and rapid results are not possible
Solution Approach 1:
The patent replaces the mechanical/chemical fire assay process with an X-ray based analytical method. Instead of using crucibles, cupels, and high-temperature heating, the invention uses X-ray fluorescence spectroscopy to directly analyze gold concentration in samples, eliminating complicated sample preparation and labor-intensive procedures while maintaining analytical accuracy
Solution Approach 2:
The patent changes the fundamental measurement parameter from thermal-based (fire assay at 1100°C) to electromagnetic radiation-based (X-ray fluorescence). This parameter change allows for rapid analysis without high temperatures and eliminates the need for complex sample preparation steps required by traditional fire assay methods
2Productivity
If small mass of sample (20-50 g) is analyzed by fire assay, then the analysis can be completed, but significant sampling errors are introduced for inhomogeneous ore samples
Solution Approach 1:
The patent replaces the physical sampling and processing method with direct X-ray fluorescence analysis. This allows for analysis of larger, more representative sample masses without the sampling errors inherent in small-sample fire assay, while still providing rapid results
3Reliability
If original sample is destroyed in fire assay process, then the analysis can be completed, but subsequent reanalysis is prevented
Solution Approach 1:
The patent replaces the destructive fire assay process with non-destructive X-ray fluorescence spectroscopy. The original sample remains intact after analysis, allowing for subsequent reanalysis, archival storage, or alternative analytical methods while maintaining accurate gold concentration measurement
4Productivity
If gamma-activation analysis method is used to analyze gold, then rapid results can be obtained, but accurate determination requires accurate knowledge of X-ray source intensity and energy spectrum which is highly susceptible to temperature variations
Solution Approach 1:
The patent introduces an internal standard element (e.g., cobalt, nickel, copper, zinc, or manganese) as an intermediary reference within the sample matrix. This internal standard serves as a built-in calibration reference that compensates for X-ray source intensity and energy spectrum variations, allowing for accurate gold quantification without requiring precise knowledge of the X-ray source characteristics
Solution Approach 2:
The patent implements a feedback mechanism where the signal from the internal standard element is used to normalize and correct the gold signal. By monitoring the internal standard's response and using it to adjust the gold concentration calculation, the system automatically compensates for drifts in X-ray source performance, maintaining measurement accuracy over time
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 approach significantly reduces measurement errors caused by X-ray source variations and sample handling inaccuracies, enabling accurate and rapid determination of gold concentration with improved precision, potentially below 3-4% accuracy.
Implementation Method 1
simultaneously irradiating the sample and the reference material with Bremsstrahlung X-rays to thereby produce activated nuclei in the target element and to produce activated nuclei in the reference element
Implementation Method 2
detecting deactivation gamma-rays from the irradiated sample and deactivation gamma-rays from the irradiated reference material
Data Source
AI summary
A method to determine a concentration of a target element in a sample is provide. The method comprises (i) positioning a sample containing a target element with respect to a reference material containing a reference element, (ii) simultaneously irradiating the sample and the reference material with Bremsstrahlung X-rays to thereby produce activated nuclei in the target element and to produce activated nuclei in the reference element, (iii) detecting deactivation gamma-rays' from the irradiated sample and deactivation gamma-rays from the irradiated reference material, (iv) determining a first number of detected deactivation gamma-rays from the irradiated sample and a second number of detected deactivation gamma-rays from the reference material, and (v) determining the concentration of the target element in the sample by first normalising the first number of detected deactivation gamma-rays from the irradiated sample by the second number of detected deactivation gamma-rays from the reference material. The variation of the reference element to target element cross section ratio over a range of electron beam energies is less than a predetermined measurement accuracy.