In all geologic time, the responsibilities are on our generation ... including you ...

4.2.4 Separating Minerals by Floatation and Vibration

It's possible to separate some minerals by their density, once we have a sieved collection of grains of the same size.

Just vibrating a bed of same sized grains will separate mineral grains into layers fairly well based on their "weight" in a centrifuge or in lunar gravity. The denser grains fall to the bottom.

Pouring material into a liquid of intermediate density will quickly separate a desired grain by floatation, though it must be dried thereafter and the fluid recycled. Floatation can be fine tuned based on the theory discussed below.

In orbital space, zero gravity helps in this process, as a centrifuge can provide different levels of artificial gravity as different minerals settle at different rates.

The quick & dirty theory on floatation

Floatation is based primarily on surface phenomenon, not the specific gravity of the mineral.

Different materials have different affinities to a selected liquid and the air bubbles introduced. The surface tension of the liquid is essential to fully understanding the process. Frothing reduces the surface tension of the liquid. Of interest is minerals' "wettability" or repellant properties, relative degree of readiness to adhere to bubbles, and affinity for certain types of chemical compounds or reagents.

Sulphide minerals of all types and sizes are the most easily floatable.

On Earth, floatation is often opted because of its simplicity, selectivity and flexibility. Frothing and separation processes may be fairly interesting in low gravity. The downside in space is the need to stringently recycle the liquid used for the floatation, as long as volatiles remain in short supply in earth orbit.

The quick & dirty theory on "gravity concentration"

There are two processes at work:

  1. Small particles tend to settle at the bottom, and large particles at the top.
  2. Given particles of the same size, heavier particles (i.e., higher specific gravity) will settle down further. > Manufacturing, Industry > Materials Processing > Vibration and Flotation


PERMANENT needs a PHP / MySQL (actually, MariaDB) programmer. Are you a PHP / MySQL programmer interested in getting into space development as a career, or already working in space development? Or do you know somebody else who might be interested?

There is an ongoing process to update this website in 2019 with a target relaunch in 2020.
This website is actually very out of date. Much of the website text content was written in the 1980s to early 2000s, but that's a different matter. As regards PHP / MySQL, some offline databases go into the 2010s, as regards professional publications, engineers, companies, etc., and this is what we need programming help with. We are updating our databases on people, organizations, publications, and other things, for open source space development for all.

The current status is we have some working databases which we have been using internally for a long time for organizing professional publications, and to track people (authors, R&D people, other professionals, quality volunteers, journalists, etc.) and organizations. We want to put information online for the general public pending a security review of the programming code.

Step 1 is fixing some bugs in what we already have, the PHP code. It is functional, and been used a long time, but there are some bugs.
Step 2 will be improving the system. Some small improvements would help its usability.
Step 3 will be a security check for putting it online for the general public to be able to access and use, but with reasonable protection against hackers.
After Step 3, the main mission is accomplished, as regards PHP / MySQL, though of course we hope to keep people engaged and happy, and the sky's not the limit.

This is a volunteer, unpaid role at this point in time. A limited paid role would be considered on a tight budget, such as for at least bug fixing with some minor improvements, and/or a security review of our code before it goes online publicly. If you or one of your friends or associates may be interested, please send an email to spaceprogrammer at ... of course this domain.

Reasons to do something yourself:

  • It will help save life on our special planet -- be part of the solution in your generation.
  • It will create and secure a better future for your children and grandchildren.
  • It could be an interesting, cool, and a fun adventure for your life!

You can join us and volunteer to help out,

... or ...

If you're short on time, you can just donate:

The Permanent Space Development Foundation, Inc., is a 501(c)(3) nonprofit organization.
If you would like to make a quick donation to our humanistic cause,
then please click on one of the buttons below (which go to PayPal).

... or by cryptocurrency (which is NOT tax deductible), you can donate into any of these wallets:





... or ...

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Text by Mark Prado, Copyright © 1983-2021, All Rights Reserved.
Many website artistic design elements by Sam Fraser, Copyright © 1999-2021, All Rights Reserved.

Except where specifically stated otherwise,
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