Use Quantitative Yield Analysis to Reveal Hidden Secrets in Your Sand & Gravel Deposit  

Managers and operators with the best information make better-informed decisions and have more profitable businesses. Learn more about using Quantitative Yield Analysis for sand and gravel deposits, to gain profit-lifting insights into your raw material.

Have you ever heard a story about an aggregates project in which millions of dollars were spent to purchase, permit, and develop property and plant, only to find that the deposit was radically different than the exploration program indicated?

Did you wonder whether those kinds of mistakes could be avoided if better information was available to decision-makers? You are not the only one.

Successful mine and pit operators know that understanding their deposit leads to better decision-making in the rest of their business. This translates into more profits.

However, if you have ever tried to evaluate a sand & gravel reserve or resource, then you know that determining a yield factor with accuracy is difficult, especially if you will be producing multiple products. So, aggregates businesses have long settled for yield and reserve estimates based on approximate indicators like:

  • Rules of Thumb
  • Sand/Gravel ratio from drill logs
  • F.M.
  • % minus #200 / 75µm / 63µm
  • % retained on a critical sieve
  • Guesswork

But leaving the fate of your business to an approximation, rule of thumb, or a guess can lead to unnecessary mistakes. Often, these become apparent only after you have spent millions on property and plant. A better way is to use more of the useful data that is available to you to identify and mitigate your risks:

  • Actual raw material gradation data
  • Products and production data from your existing operation
  • Project assumptions if you are making a change or an acquisition
  • Mathematical models to bring it all together.

Quantitative Yield Analysis

Those mathematical models are a form of “quantitative analysis” that is tailored specifically to the needs of people making decisions about sand & gravel deposits. Quantitative analysis has several meanings but is most famous for driving the algorithms that attempt to model and take advantage of the behavior of financial markets. But what does this have to do with low-tech sand & gravel mining?

Quantitative yield analysis of a sand & gravel deposit is based on the idea that when making your product or products, you will “run out” of one grain size or fraction first. This fraction will limit how much of a graded product you can physically make from your raw material.

The quantity of this fraction can be used to estimate more accurately the percentage of your raw material that can be turned into a saleable product (the theoretical yield).  This value can be used to make more accurate Resource & Reserve estimates.

Thus quantitative yield analysis gives more accurate insights into your deposit that are simply not feasible with other methods. These insights help you evaluate whether an exploration target, acquisition, project, or existing pit will be a winner or a loser.

  • Estimated tons of each product, if more than one are made.
  • How the yield will rise or fall if the target production volumes are changed.
  • Optimal production mix to achieve the highest possible yield.
  • How changing the target product gradation can affect the yield.
  • What will the waste look like? 
  • How much would a corrective boost the yield of your deposit, what its gradation should be, and what ratio is optimal?
  • Is the deposit being fully utilized (especially important in dredging operations)?

Sound complicated? Possibly, but having this kind of information at your fingertips is powerful. It will guide you to make better decisions that will combine to boost the overall profit of your operation:

  • Acquiring the right properties
  • Permitting only what can be mined economically
  • Effective mine design & planning
  • Engineering your plant right the first time
  • Plan your operations and sales around what is possible with the deposit

Is it perfect? No, it is not. The accuracy of the results depends on representative samples of the deposit that account for its natural variation. It is not possible to perfectly model a deposit until it is mined. But, all other things being equal, quantitative yield analysis is far superior to using other indicators.

Case Studies

The advanced information made available with quantitative yield analysis has become crucial for many managers that prefer to make informed decisions in their business.

For example, we recently used quantitative analysis to quickly advise a client whether an exploration target would be a viable concrete sand resource, and why. The analysis alerted the client to a problem in the deposit that would have been catastrophic if discovered only after $1 million or more was spent on acquisition, permitting, and development.

Results are about more than avoiding mistakes, too. Two of the largest aggregates producers in the United States use quantitative yield analysis to evaluate fine aggregate exploration targets in a fast-growing region. Finding a good target is challenging due to:

  • Notoriously fine deposits
  • The difference between high-value, medium-value, and no-value deposits is dangerously small.
  • Acquisition, permitting, and development are expensive and time consuming due to:
    • Environmental factors
    • Competing land uses
    • Community opposition

Picking the wrong deposit could squander tens of millions of dollars.  However, these companies used quantitative yield analysis to select and develop deposits with the highest probability of economic success.

Operations Support

Quantitative yield analysis fits well into your larger efforts to reduce risk and the number of costly mistakes in your ongoing sand & gravel operation, too. More accurate yield and resource estimates will enable you to track production performance and communicate useful information to operators.

One of the producers mentioned above also uses quantitative yield analysis in their dredging operations. This producer has reduced costs by 4-5% at each site by:

  • Ensuring proper depths are consistently achieved
  • Reducing waste, re-handling costs, and environmental expenses by planning around low yield parts of the deposit
  • Designing stripping campaigns to remove the optimal amount of fine sand overburden

Managers and operators with the best information will make better decisions and have more profitable businesses. Quantitative yield analysis should replace your old deposit indicators because it is more accurate, addresses more risk factors, and is a foundation for making data-driven decisions in your business.

Learn More

If you would like more information about quantitative yield analysis, contact us here at Lapis Global Consulting. We want to help you get the most out of your raw material deposits by making better-informed decisions about your deposit and extraction activities.


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