I suggest our Wastewater re-Purification System which just generates less than half percent than conventional WWTP technologies and instead of biological slurry ours generate inert sediments of low humidity content and ready for recycle or safe nature disposal.
I am in agreement with the others on a few of the ways to know the concentration of your slurry. If this was my operation based on the information given I would do and average dry weight delivered over time as suggested. You could also have a weighted lime vat and a water meter. This would give the weight over time versus water flow over the same period. You could also weigh a sample of the slurry many times to get an average pounds per gallon of the slurry. Subtract 8.34 lbs/gallon water weight = lbs/lime pergallon calculation based on sampled volumes. Many was to accomplish this task.
What is the purpose of lime addition in water treatment plant? Lime is added to adjust pH, to provide alkalinity for alum, lime soda softening process.
If I am properly understood that you want to determine the strength of lime slurry. You need to know CaO content in Lime you are using. How much alum you are adding to make the slurry. This will give strength of Lime slurry as CaO g/L
Do you have the manufacturers documentation? The auger is most likely a fixed volume, so the documentation should tell you how much lime is added per revolution of the auger. Math will tell you - revolutions by amount per revolution divided by your amount of water = soln strength.
You should be able to determine the solution concentration by measuring the solution TDS (total dissolved solids) and the make-up water TDS and then calculating the solids addition.
You can determine concentration my measuring the density (quick), or solids by evaporative drying in an oven (slower). If you can get samples at 4-5 settings around the normal area, you can plot the density and fit a curve to it. (auger setting vs. density). This is assuming that there is only a single variable. Multivariate curve fitting will also work, but you will need more data points.
Roger, what you need to do here is a measurement of auger output over time. Use a scale and a stop watch to determine output for a give time. This will give you a weight calculation over time.