[mblanco2000]

I am new to the chemistry world, and blending of chemicals.  We are a very small business and have just set up a small blending facility to blend some of our existing products.  Now with this new equipment it also gives us the capability to blend other chemicals that fit into our industry.  It will allow us to expand our line card, so to speak.

One thing that I am trying to figure out is how to blend chemicals by liquid weight rather than liquid volume.  I have few raw chemicals that I would like to try to blend together by weight, but I am at an impasse here.  For example, if I have three chemicals:

chem A
chem B
water

That I want to blend together by weight how should I go about it.  I weighted chem a, b, and water @ 50 mL to be able to project that out into how large a batch I wanted to make, but I am not sure that is the right way to do it.  I actually talked to one person and he was saying that I would need to get the specific gravity from the MSDS sheet and do some sort of calculation to determine the amount of chemical to get to my desired percentages.  I have searched the internet on this subject and not found anywhere to help me out.  Hopefully I am in the right place for this.  Any help is appreciated, and if I need to give more information please let me know.

[Stepan]

What is the batch size: g, kg, tons? What kind of measuring tools do you have: scales, volumetric cylinders, hygrometers? how viscous are the components? What precision do you need to achieve? 

[Borek]

Basically you should be able to do all necessary calculations knowing relationship between density (or specific gravity - they are not the same, but usually close enough), mass and volume. d=m/V. Solve for m or V whenever needed.

[mblanco2000]

The batches that I am blending typically are around the 600 mL mark.  Once I start measuring everything by liquid weight I will start using g.  I just need maybe an example that someone can walk me through so I can grasp what I am doing here.

[Stepan]

OK, your components are
A- d=1.1g/cc
B- d=0.8g/cc
W- d=1.0g/cc
Your target mixture is A/B/W=20/50/30 wt% you target batch weight is 600g

1. If you do have scales:You measure A=0.20*600=120g; B=0.5*600=300g; W=0.3*600=180g. and then mix them together. Note, sometime it does make a difference in which order you mix the liquids.
2. If you do not have scales, but you have measuring cylinder. Volume of liquid is V=M/d:

V(A)=120g/1.1=109.1cc
V(A)=300g/0.8=375.0cc
V(W)=180/1.0=180.0cc

You measure exact volume of each liquid separately, and then blend them.

[mblanco2000]

I just realized how I spelled Liquid.  Anyway, thanks for the response Stepan.  When I look at your example:
A- d=1.1g/cc
B- d=0.8g/cc
W- d=1.0g/cc

The measurements that are above I assume is specific gravity.  The reason I am assuming this is that W is = to 1.

I do have digital scales that I will be using for making my calculations on these blends.  After reading your explanation it leads me to another question.  Since all of the chemicals in the example have different g/cc wouldn't it be a bit more complex than just taking A=.20*600=120g?  Since A is 1.1g/cc I would think one might use slightly less than 120g to make the 20% in a 600 gram batch.

Since you have such a better grasp on this than I do, I am wondering if you would be willing to talk w/ me on instant messenger/phone or something.  I have yahoo messenger and my id is raiderred77077 just let me know if we can talk more in length.  Thanks so much.

Also is I am searching amazon.com as we speak to find a book that would help me with these basic chemistry issues I am running into.  Can anyone recommend a book I should pick up to conquer these hurdles?

[Stepan]

If you have scales, you do not need to worry about specific gravity (actually it was density). You weigh exact weight of each component and blend them to make your solution.

You can call me 1-(519)-642-1122 (Canada) or Skype: stepan_reut